This is a Streamlight Weaponlight known as the TLR-6, model 69282.
Based on the popular ultra-compact TLR-6" this non-laser model is designed to securely attach to the trigger guard on hand guns and features tool-less battery replacement without removal from the weapon.
Features:
C4 LED light 100 lumens
Serialized
Polymer construction
Fits G26/G27/23