The CRL Jackson 21101 Series Overhead Concealed Closer with "A" End-Load Hardware Package consists of a Closer mechanism, which depending on the selected spring size and function, is suitable for a range of doors from 30” to 48”(762 to 1219 mm) wide. The Closer is packaged complete with Cat. No. 20640 Mounting Clips, 202000 End Load Arm, Type "AE" 20728 Bottom Pivot Set for Threshold mounting, and complete installation instructions. The Closer has dual independent valves for closing operation (one valve for closing, one valve for latching). 90 and 105 degree, Hold-Open and Non Hold-Open models are available. Closers fit into standard 1-3/4" x 4"(or larger) header extrusions.