TM 100 Model (Power Trigger Mechanism) Is simple to install on any weapon with a standard trigger guard. The unique design of the mechanism allows it to fire most weapons if placed anywhere inside of the trigger guard. The simplicity of the set up allows the trigger mechanism to be moved from one weapon to another easily and quickly. The TM100 fires the weapon by a very slight suction on the blue tube in the picture which is attached to the control box. The control box is attached to the stock of the weapon with a Velcro cinch strap. The mechanism operates on 12 volt DC power and comes with a pigtail that can be attached to one of the batteries in your power chair or attached to an auxiliary battery. Battery not included. If you order this on-line your credit card will be charged $18.00 for shipping for orders shipped within the 48 Continentil U.S.A.