The Corbin Russwin Door Closer Hold Open Arm has been around for the past 40 years. This replacement hold open 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. This is considered a Friction Hold Open Arm because as the arm rotates the arm tightens on itself and holds the arm in the open position. This arm is also known as the A1 arm. Corbin Russwin part # 688F77.