What i had hoped - SureFire X300 Handgun Weaponlight Remote Tailcap Switch

well made, easy to install, momentary (not clickie), works as expected, allows one-hand operation of whatever seeting you wish, momentary, just hard enough pressure that you can decide when you want the light on (vs it always going on whenever gripped). not cheap but worth it if you're serious about your defense firearm.

one note: due to the long stiff extention, i worry about it being hit sideway, possibly damaging it, so i wrap a short piece of electrician's tape around it and the trigger guard. easy to remove when replacing batteries. its likely not a problem, but gives me peace of mind...