Plastic piping left over from underfloor heating installation. 14mm external, about 10mm internal.
Several pieces available, approximate lengths in metres are:
3, 8, 26, 1.8, 2.5, 18.8 & 12.
It's stiffer and much sturdier than garden hose. It must be useful for garden or art projects!
Plastic tubing 14mm (Malvern WR14)
This offer has been gifted to someone and is no longer available.