The Norton 9304BCH-689 Door Closer Surface Mounted With Hold Open-Back Check Silver Alum Painted Finish. The 9304BC-H-689 Is a Size 4 Non-Handed Light Duty Commercial Door Closer Ideal For Use on Storefront Doors. Friction hold open arm, Adjustable backcheck standard • Regular and top jamb mounting, Norton 9304BC-H-689 Silver Alum Painted Finish Is Certified ANSI/BHMA A156.4, Grade 3. Adjustable Backcheck Cushion Valve Provides control of the door in the opening cycle, beginning at approximately 75° of the door opening. It slows/cushions the door opening.