ANSI A156.4 - Grade 1 Adjustable Spring Power Multi-Size Range 1 to 5 Each PR40 Series Closer is Conveniently Packaged with Instructions Delayed Action Closing Model for Handicap Entrances UL Listed Warranty Information and Cross Reference Chart Available C.R. LAURENCE PR42A CRL Aluminum Adjustable Spring Power Size 2 - 5 Surface Mount Door Closer. When demanding closer specs are required, consider our PR40 Series Surface Mounted Door Closers. Recommended for high traffic areas, such as public buildings, airports, and shopping centers. Closing and latching speed controls are independently adjustable, and adjustable backcheck is a standard feature to prevent damage to the closer, door, and adjacent surface should the door be violently swung open due to wind or heavy pedestrian traffic..