A fluorosilicone inner liner. Standard silicone is excellent with coolant, water and air but swells and breaks down in contact with petrol, diesel and oil. The fluorosilicone liner gives hydrocarbon resistance inside while keeping silicone's heat resistance and long life outside.

Wrapped silicone elbows in 45 and 90 degrees, 13mm to 51mm internal diameter, in black. They have a fluorosilicone inner layer, fine mesh polyester yarn reinforcement and a wrapped VMQ silicone outer that gives a period cloth-wrapped appearance rather than modern gloss.

It reads as period rubber rather than obviously modern silicone, which matters on classic, vintage and restoration work where a glossy hose looks out of place. Underneath it is entirely modern - you get the correct look with fuel compatibility and silicone durability.

Yes - the fluorosilicone liner handles modern ethanol-blended petrol as well as diesel, oils and fuel vapour. That is a large part of why people fit it to older vehicles: original fuel hose from before ethanol blending degrades from the inside on modern pump fuel.

-60C to +180C with a +200C peak. Working pressures run from around 2.8 to 12.33 bar and burst from 8.5 to 37 bar depending on diameter, built to SAE J20 R6 with fine mesh polyester yarn reinforcement.

Yes, and it should be used there. A crankcase breather carries oil mist, which destroys plain silicone over time even though nothing liquid is obviously flowing through it. Breather and catch-can plumbing is one of the most common places the wrong hose ends up.