Steam Wand & Manual Group Spring for La San Marco A 12 x 15 mm spring used in La San Marco steam wand assemblies, and also shared with the manual-fill valves. SPECIFICATIONS Size: 12 x 15 mm COMPATIBILITY Fits: La San Marco steam wands Works with: manual-fill valves INSTALLATION Simple DIY swap. PRO TIPS This spring is shared between the steam wand and manual-fill valve assemblies, so it's worth keeping a spare on hand if you're servicing either one.