This letter agreement may be executed in two or more counterparts, each of which shall be deemed an original, and all of which together shall constitute one and the same instrument. The exchange of copies hereof, including signature pages hereto, by facsimile, e-mail or other means of electronic transmission shall constitute effective execution and delivery hereof as to the parties and may be used in lieu of the original letter agreement for all purposes and shall be deemed to be original signatures for all purposes.