Vacuum valve. For greater accuracy it's important to know the vacuum at the system. That's why the 18975 features an extra 1/4" side port to attach the electronic vacuum gauge right at the system. Can also be used to isolate the system for pressure hold tests.
Core removal access. Lets you evacuate and charge through an unrestricted line for substantially increased speed and higher ultimate vacuum.
Core replacement.
Recovery valve. Core removal for maximum efficiency and speed.