This is a 2.5x6mm x 25m length black Ultimate Racing Silicone Fuel Line. This ultra thick fuel line is an excellent choice for virtually all nitro racing applications. Made from special heat resistant silicone, this line is soft enough to bend around tight areas, while remaining firm enough to resist kinking. With an outer diameter of 6mm, this line fits perfectly into the fuel tanks. This fuel line has been tested and trusted by many National and European campions, so it’s the real professional choice.