CMMG's Mk4 T 5.56mm Upper Group features a RKM11 free-floating KeyMod handguard for nearly unlimited customization options. 16" barrel with a medium-weight taper profile boasts a removable A2 compensator attached with 1/2"-28 threading. Exceptionally durable forged 7075-T6 aluminum M4-type upper receiver. Includes the upper receiver, ejection port cover, forward assist, barrel subassembly, handguard with barrel nut, charging handle and bolt carrier group. CMMG lifetime quality guarantee. Made in USA.