VISM MOS 500 590 Handguard Tan The Vism MOS 500 590 Handguard has a low profile design with M-Lok Slots on both sides and the bottom for ample accessory mounting options. This handguard replaces the original factory handguard with quick and easy installation. It is constructed from reinforced, heat-resistant fiberglass reinforced polymer composite. This handguard fits Mossberg 500, 590, and Maverick 88 shotguns. All mounting hardware is included.