Opening damper DC153 Helps to prevent the door and door handle from hitting a return wall. Simple fitting into guide rail. Opening damper continuously adjustable up to an opening angle of max. 130°. Does not replace a door stop. Specifications Type of product Opening damper Close Sliding arm DC892Sliding arm for concealed door closers. Sliding arm DC894Double action guide rail arm G894. Opening damper DC157Opening damper for sliding arm.