UTG= cheap Airsoft crap.
I've never liked running pistol lights on a rifle. They flood well but don't have enough throw, even the X300. If you're ONLY doing room interiors they'd do, but I've had to do far too much exterior work with a whitelight. A G3, Scout or now a Fury is a better option in an offset rail mount at 10 oclock.
"And Shepherds we shall be. For thee, my Lord for thee. Power hath descended forth from thy hand, that our feet may swiftly carry out thy command. So we shall flow a river forth to thee and teeming with souls shall it ever be. In nomine Patris, et fili, et Spiritus Sancti. Amen."