Corbin Russwin DC6210689M54 Parallel Arm Adjustable Door Closer The Corbin Russwin DC6210689M54 Parallel Arm Adjustable Door Closer is a heavy-duty commercial door closer engineered for the relentless traffic of schools, hospitals, retail, and office buildings. Independent valves let you tune sweep speed, latching speed, and backcheck to match the opening's weight, wind load, and gasketing. Corbin Russwin is a heritage commercial hardware brand specified on institutional, healthcare, and government buildings for ANSI Grade 1 mortise and cylindrical locks. At RightSet Hardware, every Corbin order ships with our Right Fit Promise — verified specs, accurate fitment guidance, and friendly support from a team that actually knows door hardware. If it doesn't fit your opening, we'll make it right. Why pros and homeowners choose the Corbin Russwin DC6210689M54 Parallel Arm Adjustable Door Closer Adjustable closing and latching speed. Independent valves let you tune sweep speed and final latching action for the door's weight, hardware, and traffic. Adjustable spring power. Sized for the door width and weight on the opening, with adjustment to fine-tune for wind load and gasketing. Built for high-traffic commercial use. Cast-iron body and forged-steel arm engineered for millions of cycles on schools, offices, and hospitals. Non-handed installation. Mounts on either hand of door without separate left-hand and right-hand SKUs. Backcheck protection. Hydraulic backcheck cushions the door at the end of the swing to protect walls, hardware, and the closer itself. UL listed for fire-rated doors. Tested and listed for use on labeled fire-door assemblies where a positive-latching closer is required.