The material is flimsy but it works on my older style 5g carboy. The cooling rod sticks up pretty high as well but it might not be so with a 6gal carboy. I was thinking of getting a large hose clamp to secure the base to the carboy as an extra precaution. I’d recommend this item because I have not found any alternatives. Coolstix really helped me brew at colder temp in my uncooled garage in Southern California heat wave!

I used this in fermenting a Pilsner. While the design did fit a coolstix thermowell and airlock- I thought it was unable to make a tight seal and so CO2 leaked around these openings. Since that time I have been using PET carboys and the thicker bunge designed for the coolstix thermowell and airlock. Because the bunge is squeezed by the opening upon insertion- to me it seemed to seal much better.