Ensure functionality and safety with your compatible Descent transmitter by always using flow restrictor and air spool parts. Kit includes both a flow restrictor and air spool, but only one is used depending on installation. The flow restrictor should be installed on a Descent transmitter which is attached directly to the high-pressure port on a regulator. The air spool should be installed on a transmitter when attaching to a high-pressure hose. See the quick start manual for more details.