The Laser Ammo TA/DB Dual Function Back Cap is a combination between the Digital Boresight cap and the Dry Dire cap. The Dry Fire cap is used to enhance dry fire practice with point of impact recognition / feedback. The Digital Boresight cap is used to convert the SureStrike into a digitally controlled bore sight activated by trigger pull. The transition between the two functions is done simply by holding down the primer part of the cap (with a pencil or any other similar object, even your finger) for 7 seconds. A double flash will indicate the transition between modes. The Dual Function back cap can be used to replace any cap on all SureStrike cartridges and can be used with all available caliber adapters.