Standard elbows in 45, 90, 135 and 180 degrees from 6mm to 102mm; Fuel & Oil fluorolined elbows in 45 and 90 degrees from 6mm to 102mm; Long Leg Fuel & Oil elbows with 300mm legs from 13mm to 76mm; and Classic Wrapped elbows in 45 and 90 degrees from 13mm to 51mm.

Measure the angle between the two pipe stubs. 45 degrees is a gentle change of direction, 90 a right-angle turn, 135 a shallow return, 180 a full U-turn. If you are between sizes, the more open angle is usually better - silicone flexes a little, but forcing an elbow tighter than moulded stresses the joint permanently.

The 45 and 90 degree elbows have 150mm legs each side, 300mm total. The 135 and 180 degree elbows have 100mm legs, 200mm total. The Long Leg Fuel & Oil elbows have 300mm legs and 600mm total. Trim with a sharp blade, leaving at least 25-30mm of straight leg for the clip to seat on.

Standard silicone to SAE J20 R3 for coolant, water and air. Fuel & Oil fluorolined to SAE J30 R6 for petrol, diesel, oil and fuel vapour, including E5 and E10. Standard silicone swells and breaks down in contact with hydrocarbons, and that includes breather lines carrying oil mist.

A fluorolined elbow with a cloth-wrapped outer that reads as period rubber rather than modern glossy silicone. It suits classic, vintage and restoration work where a smooth silicone hose would look out of place, while giving modern fuel compatibility and silicone durability underneath.

Order by internal diameter, matched to the outside diameter of the pipe stub it slides onto. Measure the pipe with vernier callipers, not the old hose - hose stretches in service and reads large. If the two ends are different sizes you need a reducing elbow rather than a plain one.