The Momentary Remote Pressure Switch.
 MOMENTARY and CONSTANT switch that activates particular mode the light has been set to.
Designed to fit on any long platform it's a solid combination when used with the optional mount (NOT INCLUDED).
Made to be fit into the integrated pressure switch pocket of a foregrip the pressure switch can also be attached with hook and look (not supplied) to any platform that does not have an integrated pressure switch pocket.