Viridian lasers / taclights automatically ignite (if desired) when drawn from an ECR INSTANT-ON equipped holster. Do you have a favorite Viridian fitting holster that doesn't have ECR? Simply apply this ECR INSTANT-ON(TM) Holster Upgrade Kit and you will have automatic light / laser ignition when drawn. This kit comes with everything you'll need for an easy upgrade. Follow directions thoroughly for best adhesion. HOLSTER NOT INCLUDED