"I've used these reducing tees a few times to tee off a 22mm pipe. Always reliable, never had a problem with them. They also work well on the older 3/4 size copper pipe, where push fit and solder 22mm won't fit."
"Fitted two of these. The threads were very loose and so I used a generous amount of Hawk, including the pipe/olive joint. Despite this, all of these fittings needed to be over-tighted to loose slow leaks. So, based on my experience, the evidence is that this is a poor quality fitting. If you decide to try it, then I would definitely ditch the olives and use better quality brass olives and be very very generous with your sealant."