This rubber carboy stopper has two holes drilled (1/4" and 3/8") to accomodate both an airlock as well as a thermowell temperature probe.
A thermowell temperature probe will allow you to detect the temperature of your wort through direct contact.
Comes in 3 sizes:
- #6.5 - Glass Carboys
- #10 - Better Bottle
- #2 - Bucket Fermenter, BrewBucket
#2 sized stopper only contains 1 hole, for the thermowell
**This stopper can also accommodate a racking cane instead of a thermowell probe.