This #10 silicone 3-hole stopper is used alongside the BrewBuilt CoolStix. The holes are for a 1/2" CoolStix, an airlock and a carboy thermowell.

The holes measure 0.500", 0.413", & 0.375"

Compatible with 6 & 7 gallon Fermonsters and our Plastic PET Carboys listed below under "Related Products".

Please note: the stopper will fit all sizes of Fermonsters, however we only recommend using the 1/2" CoolStix with the 3 & 6 gallon sizes. This is due to dimensional restrictions and cooling power limitations.