The unit is well built and substantial but lacks a few things. You have to buy (from them or elsewhere) the flexible connectors to join up the 50mm waste pipes. This product is a plastic (HDPE) moulded box basically so the price (£500)is quite high for what it is. Why they wouldn't mould in a threaded connection or a built-in adapter from HDPE to ABS or PVC makes one question the design. Perhaps the most annoying thing is the clean-out opening. It's 40mm-ish outlet that nothing really fits into or on. You have to adapt a 50mm stop end to close it off. Since you can't really use the trap without this opening closed off. Again they should have moulded in a screw-out plug to close this off. The internal opinion the clean-out is maybe 25-30mm, if you have collected a lot of gunk it's going to be hard to clear the clean-out. There is a larger opening in the top, (maybe 5 inches) but you would have to dip your hand into the trap to clear a blockage. Again not well thought out. The installation is quite new and time will tell if these are fatal issues. Over prices for what it is, but seems to do the job.... so far.