Arisaka Defense Tailcap Adapter Streamlight HL-X DETAILS The Arisaka Defense Tailcap Adapter for the Streamlight Protac Rail Mount HL-X weapon light allows you to use Surefire Scout tailcaps and remote tape switches. Now you can easily pair your Rail Mount weapon light with laser/illuminators like the ATPIAL and DBAL with the use of Surefire SR-D-IT and TNVC/Unity TAPS dual switches. Not only does the Arisaka Tailcap Adapter make your Streamlight weapon light much more versatile, it features an O-ring (1 for CR123 and 1 for 18650 cells) to prevent the battery from moving under recoil and ensure it always has a connection. Improve the function of your Streamlight Protac with the Arisaka Defense Tailcap Adapter. Compatible tailcaps: Surefire UE (Newest version with black ring where the remote plugs in. The old gray ring version is not compatible) Surefire DS Surefire Z68 Compatible Remotes (with Surefire UE or DS tailcap): Surefire ST07 Surefire SR07 Surefire SR-D-IT TNVC/Unity TAPS Features: Designed for the Streamlight Protac Rail Mount HL-X Comes with two O-Rings to ensure the battery remains in place during recoil One O-Ring for CR123 and One for 18650 battery cells Diameter: 1.04" Length: 0.49" additional length to light (plus tailcap) Weight: 0.6 oz Streamlight’s Ten-TAP programming is still fully functional with the Surefire switches and will not change the current setting unless you purposefully change it. This tailcap adapter is machined from 6061-T6 aluminum with a Mil-Spec type III hardcoat anodized black finish. Arisaka LLC is a design and manufacturing company owned and run by shooting enthusiast and adamant 2nd amendment advocates. Arisaka Defense believes in creating no compromise products that make the accessories on your weapon system more ergonomic and usable. They offer a variety of light mounts to be compatible with every possible configuration. Each part is machined to precise tolerances and made with care to ensure a proper fit and elegant finish.