Corbin DC6210-691-M54 Grade 1 Tri-Packed Adjustable Door Closer with Sex Nuts and Bolts Satin Bronze Finish. Since the early 1800's, Corbin Russwin has produced high-quality, innovative door hardware for commercial and institutional facilities. Corbin Russwin, an ASSA ABLOY Group brand, remains a leader in locks, key systems, exit devices, door closers, decorative hardware and electronic access control.