There are two ways of attaching a scuba regulator to the cylinder valve.
- A-clamp (yoke) design: With this design, the first-stage regulator is dropped over the cylinder valve. It is retained using a large bolt and handle.
- DIN (Deutsches Institut für Normung) style: The first stage is screwed directly into the cylinder valve. DIN valves are generally considered safer than yoke-fitting style valves. This is because the cylinder O-ring is captured.