The MOE M-LOK Front Barrel Mount is a drop-in replacement for the Mossberg 590/590A1 12ga shotguns, featuring an extended length for improved manipulation. Now updated with M-LOK slots for compatibility with all M-LOK accessories, this product adds modularity to the proven Mossberg platform for sporting use, home defense, or on duty. NOTE: Not compatible with the optional Mossberg heatshield, removal is required before use. Also not compatible with 14" 590 Shockwave, 500, 535, Maverick 88, and AOW models.