These red collet clips are placed on plastic plumbing pipes in order to indicate that the water inside the pipe is hot.
FloPlast Flofit+ Push Fit Easy-Lay Pipe - 22mm x 3mtr
FloPlast Flofit+ Push Fit Elbow - 22mm - Pack of 10
FloPlast Flofit+ Push Fit Easy-Lay Pipe - 22mm x 25mtr Coil
FloPlast Flofit+ Push Fit Stem Elbow - 22mm - Pack of 5
FloPlast Flofit+ Push Fit PEX Pipe - 15mm x 3mtr
FloPlast Flofit+ Push Fit Reducing Tee - 15mm x 15mm x 10mm