Dorma RTS88 Door Closer-

Dorma RTS88 Series overhead concealed door closer for both
single and double-acting doors. 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.