Forend adapter threading: 1 7/16 16; Weight: 8.05 oz (without hardware-hardware weight: 2.7oz); Free float; Made from 6005-T651 Aluminum; Inside diameter: 1.75"; Outside diameter: W-1.95" H-2.23"; 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; QD sling mount positions at 3 and 9 o'clock; Key slots double as QD sling mount positions, made to fit Magpul QD