A clever, 2 ball valve system that: 1. Allows air into the tank to replace used fuel. 2. Allows air out due to expansion and 3. Closes off to prevent fuel escaping either by sloshing or roll-over.
Fits through an 11mm hole in the tank (Access from inside the tank is required to fit and tighten the nut). THread is 7/16 UNF. Takes 5mm hose.
FUEL TANK BREATHER VALVE #FTBV