The Arisaka Tailcap Adapter Streamlight ProTac HL-X allows ProTac Rail Mount HL-X and Rail Mount HL-X Pro lights to use Surefire Scout tailcaps and remote switches. In particular, the ProTac Rail Mount lights can now be used with the Surefire SR-D-IT and Unity AXON 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.

Installation Note – This adapter requires the use of a Surefire UE, DS or Unity Tactical Gascap tailcap to function which is not included. 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. This product is NOT compatible with the ProTac 2.0 Rail Mount Lights.

Compatible lights:

• Streamlight Protac Rail Mount HL-X
• Streamlight Protac Rail Mount HL-X Pro

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
• Unity Gascap USB-C

Compatible Remotes (with Surefire UE or DS tailcap):

• Surefire ST07
• Surefire SR07
• Surefire SR-D-IT
• Unity TAPS
• Unity Hot Button
• Unity Axon (Surefire plug)
• Unity Axon SL (Surefire plug)
• Modlite Modbutton
• Modlite Modbutton Lite (Surefire plug)

Compatible Remotes (with Unity Gascap USB-C tailcap):

• Unity Axon USB-C
• Unity Axon SL USB-C
• Modbutton Lite USB-C