THREE HOLE STOPPER #?? Drilled With One 3/8 in Hole and Two 1/4 in Holes – Direct Replacement For Grainfather GCA Glycol Chiller Adaptor

Here’s a hard to find #??? 2-Hole rubber stopper for fitting and airlock AND a thermometer or other device.  This stopper is the factory replacement for the one on a Grainfather GCA.   Use this in any configuration you can think of,  Airlocks, Thermowells, Racking Canes, or Aquarium pump powered filter arrangements and many others.  These fit most  standard glass fermenters! Fits almost all gallon jugs, 3 gal glass Carboys, and 5 gal glass Carboys.