Petrol Strimmer Fuel Line Pipe Hose Mowers Trimmer Chainsaw 2mm/2.5mm/3mm
And many other gas petrol engine machines. I.D 1/8" x O.D 13/16" / 3mm x 5mm. I.D 3/64" x O.D 9/64" / 2mm x 3.5mm. approximate not exact. The picture above shows one size of pipe and is a guide for colour and clarity.