used for connecting an OD 4inch cast iron soil stack to upvc 110. ID of the cast iron was about 93mm, so was very tight to get in, had to use a rubber mallet and silicone grease. plastic side went on smooth with just water for lubrication. The internal diameter of the coupling is approx 80mm, which is less of a reduction than some other connectors I've seen. also due to the insertion length gives good joint stability (better than a rubber clamp around the outside. was struggling to find anything that would work so glad I found this
A bit of a saver, pipe was embedded in concrete so unable to get an external connector on.
