Made by Waterway
This hot tub pipe extender fits inside pipe to extend it by 3cm.
1.5" Hot Tub Pipe Extending Connector Dimensions:
1 end fits inside 1.5"" pipe (4cm) and the other is the same external size as 1.5" pipe (4.8cm) which means it fits into a 1.5" fitting. The internal of the smaller size is the same as the internal of 2" plumbing which means you can stack these together.