Not needed for new units as they already have the new insulation.
This easy to install kit adds a chemically inert PTFE washer inside of the bowl along with replacing the insulation underneath the bowl to insure that all acid goes into the hive instead of leaking from the bottom.
The original insulation was rated very high in temp but was found to be to brittle and crumbled if bumped hard. This solution should be easy for any level of DIYer to replace.
Comes with instructions that have large easy to follow pictures!