Adapter was perfect for connecting from the drainpipe to the water butt. Only downside is that it is expensive for what you get to be honest, but saying that, it completed my project.
You can't seem to find a kit like this elsewhere but there are some problems with the design. Specifically I have used it to adapt my 25mm (ID) downpipes on my Robinsons greenhouse to a 50mm minipipe so I could fit a rainwater diverter (it's a big greenhouse!).
However the 25mm adaptor in the kit has a barb which makes the effective diameter ca 28mm, and the barb was not made of a solid plastic (not rubber) and so split my 25mm downpipe when I tried to fit it. Solution - I had to sand down the barb until it fit which was a bit of a pain - esp if you do not have a multitool.
Also the 50mm adaptor has a tendency to disappear down the pipe - a bigger lip would be good. Otherwise good.
Note to manufacturer use a soft rubber for the barb as downpipes are not thermoplastic.
Difficult to find this adaptor did the job as required, fast service from Rainwater Terrace made it quick and simple to get hold of.
In my case I didn’t need the adaptor in the end as I changed the layout, but very useful to have those `hard to find' accessories on the same website as the water butts.
This is the perfect way to connect shed's 50mm downpipe into a water butt. We couldn't find this product anywhere else. It's superb!