The active area of the DX1 measures just over 9 1/2" x 6 1/2". A series of removable keys are then situated within that area, anywhere you want. Each key has its ID number on it, letting you know which key is what in the configuration software. The DX1 comes standard with 25 keys, numbers 1 - 25 obviously, while a set of keys numbered 26 - 50 are available for purchase separately, giving you up to 50 configurable keys for any one setup reports IGN. The keys have an adhesive surface, once attached, they're set in place pretty firmly. The instructions say that to clean the keys you should just use a moist towel and wipe them clean. More