Exhibit B JOINT FILING AGREEMENT The undersigned hereby agree that the Statement on Schedule 13G with respect to the Common Stock of Numerex Corp. and any further amendments thereto executed by each and any of us shall be filed on behalf of each of us...Joint Filing Agreement • March 2nd, 2009 • Potomac Capital Management LLC • Wholesale-construction & mining (no petro) machinery & equip
This Agreement may be executed in separate counterparts, each of which shall be deemed an original, but all of which shall constitute one and the same instrument.
