SSK Firearms Scope Ring TSOB 1 inch Clear Picatinny/Weaver. 810" diameter barrel and 6 screw mount (6) 6-48x3/16 SHCS screws included Made from 2024-T4 bar stock not extrusion Matte Black hardcoat anodize Picatinny spacing with 10 MOA Lightened base. Specifications for SSK Firearms Scope Ring: Manufacturer: SSK Firearms Finish: Matte Base/Mount Type: QD mount Ring Height: 1.775 in Tube Diameter: 1 in Gun Model: Thompson/Center Contender Quantity: 1 Ring Type: Picatinny/Weaver Fabric/Material: 2024-T4 Length: 0.6 in Weight: 0.12 lb Mount Type: Weaver Gun Rail: Weaver Picatinny Package Contents: SSK Firearms Scope Ring SSK Firearms SRCE11001: Scope Ring TSOB 1 inch Clear Picatinny/Weaver