The Corbin Russwin Regular Arm for 2800 is the standard arm shipped by them for the past 40 years. This replacement regular arm will work on the older Corbin 100, 110, and 120's, and the Russwin 2800, 2810 and 2820's. Along with the DC3210 and DC6210 Door Closers. The arm is non handed and can be used for regular, parallel and top jamb mount. Corbin Russwin part # 688F95.