The 81 Series are surface-mounted holders and stops that offer the most effective shock-absorbing capacity, helping protect doors, frames and hardware. They provide rugged, heavy-duty door control. The jointed-arm design provides the most effective stop mechanism available. The shock absorber bracket is surface mounted, usually with sex bolts. The jamb bracket is mounted to the stop of the frame, so a minimum of door and frame preparation is required. The 81 Series is compatible with most door closers and features an extremely reliable hold-open function.