"Note to the previous reviewer: Unroll the pipe gently but firmly onto a flat surface, then it will be straight. Soft copper micro-bore always comes rolls: if it were supplied in straight lengths it would be ruined, and genuinely unstraightenable once it had been transported. 10mm is excellent for exposed central heating runs. I used it in a timber-framed period house and it looks good, and very unobtrusive once painted. It’s very easy to dress around uneven walls, exposed studs, and obstructions."