This is a Glock Tac Light known as the 6V, model TAC3166.
Equipped with the ultimate electronic features at a minimal weight" the GLOCK Tactical Light is designed specifically for duty use under extreme circumstances. The high-resistant GLOCK polymer casing holds Xenon-technology electronics packing high luminous power" available at the touch of the ergonomically-placed "Soft Switch". 70 lumens
Features:
Main switch (MS) Touch detent switch with Ambidextrous operation
Range (m / ft.) 100 / 328
Focusable
Light Xenon
Not dimmable