Arisaka Tailcap Adapter – Streamlight Protac Railmount HL-X

The Arisaka Tailcap Adapter was designed to allow Streamlight ProTac Railmount HL-X lights to use Surefire Scout Tailcap and remote switches. In particular, the ProTac Rail Mount lights can now be used with the Surefire SR-D-IT and TNVC/Unity TAPS dual switches, which are commonly paired with laser/illuminators like the ATPIAL and DBAL series.

One of the main flaws of the Protac Rail Mount lights is also addressed: Streamlight did not design a front battery spring into the light, so under recoil the battery can come off the front contact and cause the light to flicker or blink. To help prevent this behavior the adapter includes two different o-rings (one for CR123 cells, one for 18650 cells) which can be placed on the back end of the battery before screwing on the adapter. The o-ring ensures the battery cannot move rearward while firing.

The Arisaka Tailcap Adapter is CNC machined from 6061-T6 aluminum and MIL-A-8625 Type III hard coat anodized. Made in the USA.

This adapter requires the use of a Surefire UE or DS tailcap to function. It also does NOT work with the Rail Mount HL-X Laser model. Additionally, we do not recommend the HL-X Laser model because it is not scout mount compatible.

Streamlight’s TEN-TAP Programming is still fully functional with the use of Surefire tailcaps and remote switches in combination with the Arisaka Tailcap Adapter. The current setting is not altered unless purposefully changed just like using the stock Streamlight tailcap.

Compatible Lights

Streamlight Protac Rail Mount HL-X

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, SR07 & SR-D-IT

Unity TAPS & Hot Button

Modlite Modbutton & Modbutton Lite (Surefire plug)