It is 1 metre lengths of straight reinforced silicone hose that you cut to size - the building block for coolant runs, intake and charge air pipework, breather lines and general fluid transfer. Use it where a moulded elbow is not needed, to join hard pipework, or to make up your own hose runs on a custom or repaired installation.

The standard hose is built to SAE J20 R3 for coolant, water and air, comes in blue, black and red, and covers internal diameters from 6mm to 152mm. The Fuel & Oil version is built to SAE J30 R6 with a hydrocarbon-resistant liner, is black only, and covers 6mm to 63mm. If fuel, diesel or oil will touch the inside of the hose, you need the Fuel & Oil version - standard silicone will swell and fail.

Order by internal diameter, matched to the outside diameter of the pipe stub or joiner the hose slides over. Measure the pipe itself with vernier callipers rather than measuring the old hose, which may have stretched. If the two ends you are joining are different sizes, you need a reducer rather than a straight hose.

High-grade silicone inner and outer layers with polyester braid reinforcement between them. The braid is what gives it pressure stability and stops the bore ballooning; the silicone gives the temperature range and the resistance to ageing, ozone and heat cycling. The smooth bore keeps flow efficient and reduces turbulence.

Only gently. Straight hose has a minimum bend radius and the larger the bore the larger it is - force it round a tight corner and the bore will kink, restricting flow and creating a stress point that eventually fails. For any real change of direction use a moulded elbow. We stock 45, 90, 135 and 180 degree silicone elbows in matching sizes and colours.

Use a sharp blade or a dedicated hose cutter and cut square in one decisive stroke. Do not use a hacksaw - it drags the reinforcement plies and leaves a frayed edge that is very difficult to seal. If you are cutting more than a couple of lengths, a proper hose cutter pays for itself quickly and gives a far better joint.