1.2mm
3M Accuspray Paint Spray Gun Nozzle Refills for PPS 2.0 26612 1.2 mm Blue Use
What stands out about this design is the stainless steel that won't leach chemicals.
3M Performance Gravity HVLP Atomizing Head Refill Kit 26712 Size 1.2 Blue for
A nice touch is the metal clip that attaches to the edge.