C.R. LAURENCE PR74BCA CRL Aluminum Adjustable Spring Power Size 2 to 6 Surface Mount Door Closer. The CRL PR70 Series of Multi-Size Adjustable Spring Power Surface Mounted Door Closers are a range of Closers offering A.D.A. Barrier-Free (low opening resistance), Delayed Action models to allow adjustable delayed closing, and heavy-duty full range models for full control of heavier commercial doors. They are also available in Bright Gold and Polished Chrome finishes to complement most architectural finish requirements..