Features Include: Free float. Made from 6005-T651 Aluminum. Weight: 7oz. Hardware weight: 2.7oz. Inside diameter: 1.6″. Outside diameter: W-1.8″ H-2.16″. Engineered with advanced ergonomics for comfort and improved performance. Accessory rails can be placed at 3, 6, and 9 o’clock positions and can be joined to create continuous Pic Spec Rail. Four or more QD attachment points. Made to fit Magpul QD. Engineered to allow for low profile gas block to fit inside.