3/8" Anti-vacuum Valve - Stainless Steel
For Rancilio (and Promac/Laranzato) ONLY. Larger than the more common W_517, 1/4" valve. Allows air to escape as the the boiler heats up. OUTSIDE diameter of the male thread measures 5/8".
The W_154 gasket is your best option for this valve.
Perfect replacement for my leaking valve.