Apeks HP Twin Port AdapterThe Apeks HP twin adapter allows you to use both a submersible pressure gauge and a transmitter from a first stage that only has a single high pressure port. The twin adapter also has the added benefit of allowing the transmitter to rotate 360 degrees, which prevents the transmitter being damaged if a cylinder was to fall over. The Apeks HP twin adapter utilizes a standard 7 16 thread and is suitable for use on all manufacturers first stages.