The JK Armament 155 Booster/3 Lug Adapter in 1.125-28 TPI (JK Armament part no. JK155LTA25) is a thread adapter ring that lets a pistol booster or 3 lug mount you already own thread onto a JK Armament 155 suppressor or any other suppressor with the industry standard HUB 1.375×24 TPI mount. JK makes it in three internal thread sizes, and the 1.125-28 version is the one for SilencerCo Octane and Alpha ASR mounts, Griffin mounts and the Area419 Hellfire. It is machined from billet 7075 aluminum and finished in black Type 3 hard anodize, and it measures 1.55 inches across.

Key Specifications

• The internal thread is 1.125-28 TPI, one of three internal sizes JK makes for this adapter.
• The outer thread mates with a 1.375×24 TPI HUB mount (also written 1-3/8×24 TPI), the industry standard on JK 155 suppressors.
• It is machined from T6-7075 billet aluminum, a strong, light alloy.
• The finish is Type 3 hard anodize in black, a durable coating for a threaded part.
• The diameter is 1.55 inches, the outside size of the adapter ring.
• JK lists the SilencerCo Octane 3 Lug Mount (AC2447/AC2448) and Alpha ASR Mount (AC2632) as compatible with the 1.125-28 version.
• JK also lists the Griffin Plan A (TMA1125x28), Griffin A2 Optimus Blast Shield and Area419 Hellfire Mount (Harvest Option) for this thread size.

Frequently Asked Questions

Which mounts fit the 1.125-28 TPI adapter? JK Armament lists the SilencerCo Octane 3 Lug Mount (AC2447/AC2448), SilencerCo Alpha ASR Mount (AC2632), Griffin Plan A (TMA1125x28), Griffin A2 Optimus Blast Shield and Area419 Hellfire Mount (Harvest Option).

What does the adapter connect to on the suppressor side? It threads to a JK 155 suppressor or any other suppressor with the industry standard HUB 1.375×24 TPI mount.

Are the other internal thread sizes the same part? No. JK also makes 1.180-24 TPI and 1.203-28 TPI versions for different mount brands, so match the internal thread of your booster or 3 lug mount.

Buy the JK Armament 155 Booster/3 Lug Adapter, 1.125-28 TPI

Moving a booster or 3 lug mount to a HUB-threaded suppressor is a one-part job when the adapter matches the mount thread, and 1.125-28 is the size JK pairs with the mounts listed above. Order it from our Lubbock, Texas gun shop for fast, insured shipping, and browse our parts & accessories for more.