This #10 3-hole silicone stopper is used alongside the BrewBuilt CoolStix for Carboys. The holes are for a 1/2″ CoolStix, an airlock, and a thermowell. The holes measure 0.500″, 0.413″, & 0.375″
Compatible with Fermonsters and our Plastic PET Carboys listed below under “You Might Also Need”.
Please note: the stopper will fit all sizes of Fermonsters, however we only recommend using the 1/2″ CoolStix with the 3, 5 & 6 gallon sizes. This is due to dimensional restrictions and cooling power limitations.