O-ring 03218 Silicone

La San Marco #109252 (CTSORI0150).

3.53 mm thick, with an internal diameter of 55.25 mm. Group to boiler o-ring found in the models:

Serie new 105 multiboiler Gruppo multiboiler completo
Brewing Group 20/20 P&P Brewing Group
Delivery unit 85 Flexa-E Delivery unit
Brewing Group D. MB D. Brewing Group D. MB
Coffee unit SM MINI Coffee unit
Coffee unit SM 1 Coffee unit
Coffee unit SM 2 Coffee unit
Capsules and Boiler Group WE2 WE2 Capsules and Boiler Group WE2