The Dorma RTS88 Door Closer is an overhead concealed closer for both single and double-acting doors. It is one of the more popular overhead concealed closers on the market today. The RTS88 will consist of a steel cam, rollers, and springs housed in a compact cast iron body. Closers will be capable of being installed in minimum 1-3/4" x 4" headers. RTS88 will have maximum door opening to 90º or 105º, trim conditions permitting. Sweep and latch speed will be controlled by two noncritical adjustment valves from 90º or 105º to closed. Built-in pressure relief valve will protect the closer from abuse caused by forced closing. A mechanical backcheck combined with a positive stop at 90º or 105º will be provided to protect the door and frame. The RTS88 closer will be available with hold open at 90º or 105º, or without hold open. The product shown here is just the replacement cylinder.