Description: Fits dovetail 20mm rail. Dovetail rail extension. Can be used to conver 20mm. Features: Length:approx 100mm Height:approx 10.5mm Width: approx 20mm The distance between Hole:as the picture shown(approx) Material:Aluminum Alloy Color:Black Package Included: 1 X Bracket 1 X Wrench 5 X Screw