Here is the description from the A.R.M.S. website: A.R.M.S.® #63 Throw Lever® Riser Mount Combines all the features of the #5 with the #19!! Dual Throw Lever® riser mount. Quick detach mounting platform. Provides 3/4" of additional height for mounting optics with large objective lenses. The #63 is compatible with STANAG mounts and features a see-through channel for use with iron sights. Weight: 4.4oz Length: Approx. 5" U.S. Patent No. 5276988, 7493721 & D548811 I only had this mounted for a short time and it still loks brand new. Retail is $140 + shipping but I'm only asking $100. Prefer ftf sale in Graham/Puyallup area but will ship if buyer pays shipping.