This part has a female ASA port that accepts standard CO2 bottle threads. Normally a hose would connect to here through an adapter. You may also connect an expansion chamber or regulator to this point.
Tombstone Adapter on the Tippmann A-5 Basic Diagram v2 2009-08-06Tombstone Adapter on the Tippmann A-5 Basic 2011 Diagram
Tombstone Adapter on the Tippmann A-5 RT Body Diagram v2 2009-09-04