The Surefire Scout UE-BK light rear cap is necessary when running pressure switches remotely.
Why consider running a remote tape switch or pressure pad:
while it is possible to run the surefire scout lights with their included push button tail cap, a tape switch is more versatile. Mounting the light closest to the muzzle is often ideal, and a tape switch allows more flexibility in placement.
The Surefire Scout light rear cap allows the use of several different switch configurations.