The Stern Defense MOD4 is an 8 high-performance handguard precision-machined from 6061-T6 aircraft-grade aluminum. Finished in a durable black anodized coat, it features a secure clamp-on mounting system designed to withstand heavy recoil and sustained fire. This 8 rail utilizes a slim profile with a 1.435 internal diameter and provides full M-LOK compatibility for modular accessory attachment. The assembly includes four integrated QD sling swivel ports and ships complete with the necessary barrel nut and mounting hardware for a seamless installation on your receiver. Note: The 1.435-inch internal diameter is specifically sized to provide a slim ergonomic grip while still allowing clearance for most standard low-profile gas blocks.