Common use of Optional Redemption at the Holder’s Election Clause in Contracts

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 Notes is hereby amended and restated as follows: “At any time from and after February 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31, 2019 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 November 2016 Notes is hereby amended and restated as follows: “At any time from and after February July 1, 2019 2018 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31June 30, 2019 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:”

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 November 2016 Notes is hereby amended and restated as follows: “At any time from and after February January 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January December 31, 2019 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December June 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December June 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 Bridge Notes is hereby amended and restated as follows: “At any time from and after February 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31, 2019 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 2017 Notes is hereby amended and restated as follows: “At any time from and after February July 1, 2019 2018 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31June 30, 2019 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 Notes is hereby amended and restated as follows: “At any time from and after February January 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January December 31, 2019 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December June 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December June 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 November 2016 Notes is hereby amended and restated as follows: “At any time from and after February 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31, 2019 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 June 2018 Notes is hereby amended and restated as follows: “At any time from and after February January 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January December 31, 2019 2018 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA:”

Optional Redemption at the Holder’s Election. The first sentence of Section 7 of the 2015 June 2018 Notes is hereby amended and restated as follows: “At any time from and after February 1, 2019 and provided that the Company shall not have received either (i) initial deposits for at least eight 2 megawatt (MW) Power Oxidizer units or (ii) firm purchase orders totaling not less than $3,500,000 and initial payment collections of at least $1,600,000, in each case during the period commencing on the Issuance Date and ending on January 31, 2019 (inclusive), the Holder shall have the right, in its sole and absolute discretion, at any time or times, to require that the Company redeem (a “Holder Optional Redemption”) all or any portion of the Conversion Amount of this Note then outstanding by delivering written notice thereof (a “Holder Optional Redemption Notice” and the date the Holder delivers such notice, the “Holder Optional Redemption Notice Date”) to the Company, which notice shall state (i) the portion of this Note that is being redeemed and (ii) the date on which the Holder Optional Redemption shall occur, which date shall be not less than three (3) Business Days from the Holder Optional Redemption Notice Date (the “Holder Optional Redemption Date”).” Notwithstanding the foregoing, effective upon the issuance by the Company of December 2018 Notes for aggregate gross proceeds of at least $2.0 million pursuant to the December 2018 SPA: