The Suunto Flow Restrictor is used with the Suunto Tank POD. You should remove the restrictor only for cleaning or changing scuba gear. The restrictor must be re-installed before using the transmitter again.
The Suunto Flow Restrictor Tank POD Kit contains one Type A and one Type B flow restrictor. The shorter Flow Restrictor Type A is used when the Suunto Tank POD is installed directly to a first-stage regulator high pressure port.
The longer Flow Restrictor Type B is used when the Suunto Tank POD is connected to a high pressure hose extension, with the hose attached to the first stage regulator high pressure port.
The Suunto Flow Restrictor Tank POD Kit also contains a Suunto Tank POD Quick Guide with installation instructions.