The CYL-21 Series is a compact cylinder regulator based on the time proven design of the PR-1 Series single-stage stainless steel line regulator and is suitable for most corrosive gas cylinder applications. While normally used for low and moderate flow service, optional high flow orifices are available.The standard unit is equipped with CGA connector, integral inlet filter, inlet and outlet pressure gauges and may be ordered with extra inlet or outlet ports for inlet purging, outlet relief valves or other accessory items.