SIG Sauer M400 TREAD V2 Coil 5.56 NATO Rifle with ROMEO5 Gen II, 16-Inch

The SIG M400 TREAD V2 Coil is the TREAD that leaves the factory ready: a ROMEO5 Gen II, an M-LOK vertical foregrip, and a barricade stop already on the 16 in. stainless rifle.

TREAD V2 is SIG’s no-compromise AR. A 16 in. stainless barrel, mid-length gas, and a Matchlite Duo two-stage sit under a TREAD-engraved free-float M-LOK handguard. SIG built V2 from shooter feedback: more handguard, a cleaner trigger, Magpul’s SL-K stock. The lower is ambidextrous on the safety and magazine release, with QD cups on the receiver.

Coil keeps the V2 stainless 16 in. barrel, mid-length gas, Matchlite Duo, and Magpul SL-K, then adds the factory ROMEO5 Gen II plus an installed M-LOK vertical foregrip and barricade stop. SIG sells it as range-ready without a separate accessorizing trip. The 3-prong flash hider and 1:8 twist match the iron-sight TREAD V2.

This Coil package

This is not a bare TREAD V2. The ROMEO5 Gen II, vertical grip, and barricade stop are on the rifle from the factory. Black anodized. One 30-round magazine. The optic is a ROMEO5 Gen II, not a ROMEO-MSR.

What ships

The iron-sight TREAD V2 is the same rifle without the Coil accessories. This is a serialized 5.56 rifle and ships to a licensed FFL. See the SIG M400 collection.

Specifications and Included Items

Model: RM400-16B-TRD-V2-COIL
Caliber: 5.56 NATO
Barrel: 16 in. stainless steel, 1:8 twist, 1/2-28 tapered shoulder
Muzzle: SIG 3-prong flash hider
Operating system: Mid-length direct impingement
Trigger: SIG 2-stage Matchlite Duo, flat
Optic: Factory ROMEO5 Gen II compact red dot
Handguard: TREAD-engraved enhanced free-float M-LOK with factory vertical foregrip and barricade stop
Stock: 6-position Magpul SL-K
Finish: Black anodized
Magazine included: One 30-round polymer AR-15 magazine
FFL: Rifle; ships to a licensed FFL dealer