I would get some other things even though. The Tower stuff is often a pita to cut. Relatively brittle and has a tendency to shatter. The fitting is comprised of 1 piece although one other connection system needs two parts, the saddle-faucet and reducer. John Williamson mentioned: 20mm for 4m2? https://andyypesf.bloggosite.com/43931318/oval-conduit-options