2 1/2 inches (5 Picatinny rail slots) in length with a Picatinny standard rail mount Will accommodate Picatinny or Weaver standard red dots, scopes, and other optics. <br> Locks securely in place with quick release lock Easy to install and detach, no tools needed.<br> Fit standard 20mm Picatinny rails Durable all metal construction Lightweight, made of aluminum with black anodized matte finish. <br> Adjustable locking tension. <br> Package Includes: 1 x Tactical 1/2" Weaver/Picatinny Rail Riser , 1 x Allen key