Save time and money on the range with our 9mm SureStrike Multi Mode Back Cap. Two modes in one: laser boresight and dry fire. This device can be used on all SureStrike 9mm laser cartridges and all available caliber adapters (excluding .38SP/357, .380, .223, Makarov, and vibration cartridges). To install, simply screw back cap onto the back of your SureStrike cartridge. Back cap ships in dry fire mode. To switch to boresight mode, hold down the primer for 7-10 seconds. Once laser flashes twice, your back cap is now in boresight mode. To switch back to dry fire mode, simply hold primer down for another 7-10 seconds. Release primer after the first flash, and your back cap is now in dry fire mode. Item guaranteed for 5000 shots! Back cap protects your firing pin, so no need for an additional "snap-cap" type device. Package includes dry fire back cap, battery, and user guide.