For surgical control when using an X-Series WeaponLight (X300, X400), the DG grip switch uses a minimal center-mounted pad. This allows the operator to activate the light with finger pressure without needing to move a finger from the grip.
For Glock 17,17L,18,19,20,21,22,23,24,31,32,34,35 (rail versions), Beretta PX4 Full Size, H&K P2000 NSN:5930-01-640-9794