The Laser Grip for the Chimano family of weapons appears to be based off the Crimson Trace Glock Laser Grip.
Unlike the Pocket Laser attachment which is turned on and off via a switch, the Laser Grip in reality is pressure-activated, meaning the laser will only come out when the grip-mounted trigger is pressed. Of course, the laser stays activated in-game for gameplay reasons.
The Laser Grip's laser sight is the only laser aiming module that is available at the same time as a Pistol Light attachment. One press of the "Q"/"D-pad down" activates both gadgets if a Tactical Pistol Light is attached.