These black alloy 10-15mm dovetail to 20mm weaver adaptors will raise the scope and will fit any general sporting rifle with a dovetail eg. JW15, 10/22 etc Two options; #2; Overhang: rail 100mm long, base 75mm long, 14mm high, 20.8mm wide weaver rail. #3; Overhang: rail 100mm long, base 75mm long, 18mm high, 20.8mm wide weaver rail. See through. * please select which one/s you want. + I have 222 Loctite listed and its recommended to use on the screws.