RIS II M4A1 ASSEMBLY BLACK 01-004-08001-006 Manufacturer Model Number: 01-004-08001-006 Manufacturer: Daniel Defense Model: M4A1 RIS II Rail Assembly Type: Accessory-Rails Item Type: Accessory Finish: Black Overall Length: 12.25" Weight: 17.7 oz Shipping Weight: 1.95 Feature: Free Floating Barrel Design Feature: Mil-Spec 1913 Picatinny Rails Feature: Continuous Upper Rail Optic Adjustable Objective: false Optic Reticle Illuminated: false