The Strategic Sciences MFMD-6MM-2.1-MDSD-5/8X24-BK is a specialized, NFA-regulated hybrid muzzle system designed to function as a high-efficiency sound suppressor, flash hider, and compensator. Utilizing a 3D-printed monolithic Inconel construction, the device features a flow-through internal geometry that manages gas flow to eliminate the need for traditional baffles. This design significantly reduces backpressure, mitigates first-round flash by up to 99%, and lowers felt recoil by approximately 60%. This specific Black finish configuration is built for 6mm host weapons with 5/8x24 threads and requires 2.1 inches of over-the-barrel clearance, allowing the device to telescope deeply back over the barrel for superior weight distribution and a minimized overall footprint. It pairs the primary hearing-safe muzzle base with the SDX long extension, offering the highest level of sound suppression available in the MFMD line for 6mm platforms. Strategic Sciences MFMD 6mm (6ARC Optimized) 2.1" OTB 5/8x24 Direct Thread Black Muzzle Device & SD MFMD-6MM-2.1-MDSD-5/8X24-BK