This is a Crimson Trace Corporation Laser known as the LiNQ, model LNQ-100G.
LiNQ combines a Green Laser Sight and 300 Lumen LED White Light with Instinctive Activation(TM) for AR-Type Modern Sporting Rifles (AR-15" AR-10" M4" M16" HK416). Utilizing a secure" individual wireless connection" LiNQ offers complete wireless control of the laser and light module. The replacement grip is ergonomically designed for quick activation and mode changes" eliminating the need to reach for the rifle's forend to operate. The green laser sight" coupled with a powerful tactical light" offers high visibility in all lighting conditions" making LiNQ the ultimate illumination and targeting solution.
Features:
Front activation
Green laser
Factory sighted at 50Ft
.5 inch diameter at 50 feet