The Reptilia 15" M-LOK Handguard is a full-length, free-float rail system engineered for the AR15 platform and compatible with all M4-profile upper receivers. It utilizes Reptilia's patented turnbuckle mounting technology, which employs a reverse-threaded nut assembly to apply high-tension pressure against a standard 1.25-inch barrel nut, ensuring a rock-solid, anti-rotational lockup without the need for traditional anti-rotation tabs. Precision-machined from 6061-T6 aluminum, this 15-inch rail provides maximum modular real estate with seven sides of M-LOK slots and a full-length Picatinny top rail. The front of the handguard features angled cuts to improve ergonomics and clearance for muzzle devices, all protected by a durable MIL-STD Type III Black hardcoat anodized finish. Reptilia 15" M-LOK Black Handguard for M4 Upper Receivers 100-339