Lancer Systems Handguard, Replacement Handguard, Sig MPX, Carbon Fiber Black LCH-MPX-8 Engineered to fit the Sig Sauer MPX" Lancer's 8" Carbon Fiber Lightweight M-LOK Handguard is a drop-in replacement that offers a 50% weight reduction over the original factory unit. The carbon fiber tube is quickly installed or removed for cleaning using the OEM takedown pin. It features Magpul M-LOK attachment slots along its length for compatibility with tactical aftermarket accessories" and with an inside diameter of 1.6" it is compatible with most sound suppressors.