($25)-QD Set, ($7)-Adapter :
Quick Disconnect - Set
Includes: both the female quick disconnect unit that attaches to your Iwata airbrush hose and one male adapter that goes onto your airbrush.
Even if you only use one airbrush you will find that being able to disconnect your airbrush from the air source without turning it off or regulating down the pressure every time to be a big time saver.
Quick Disconnect - Male adapter
If you already have a quick disconnect set and would like to use more than one airbrush with the same hose, then purchasing additional male adapters makes it easy. Just install one adapter on each airbrush and you can do away with all the clutter and tangled hoses.