TIRCP - Thumb index recoil control pad. Can attach to Picatinny top rail. Includes fastening hardware. Style "slick" which is suitable for adding grip tape. One piece of 1/2" x 1" rubber style grip tape is included. The top of the TIRCP extends 14 mm (9/16") above Picatinny rail, which is about 22 mm (7/8") below typical iron sight height, meaning it is below the center of all typical optic heights. The TIRCP occupies exactly 5 Picatinny rail elevated parts and the 4 gaps in between them.