From the product description, check product page for current description, price and availability:

This thermowell fits into any 8mm Hole and can literally be installed into almost any fermenter lid. Having the thermowell attach to the lid of a fermenter is ideal as it means the penetration through the fermenter body is at the top of the fermenter not below the liquid line. This makes the whole process more sanitary and reduces the number of difficult parts to clean. This thermowell can be pushed through a bung with a 6-8mm hole but it’s also includes the duotight bulkhead fitting that you can use to attach this thermowell to the lid of your KegMenter or FermZilla Fermenter. This thermowell goes right into the middle of the core of your vessel meaning you get an accurate core reading of the liquid in the tank/vessel.

Note: If you need to shorten the 23″ length of this thermowell tube use a tubing cutter. If you want to see how to use this product you can see it featured in this video below: