Davis #376 No Spill Fuel System No-Spill is a fuel resistant bottle designed for temporary attachment to the hull, over the fuel tank vent, while fueling. It captures fuel spilled from the vent when the tank reaches a full level, fuel that would otherwise stain the hull and run into the water. Spilling fuel into U.S. waters is illegal and bad for the environment. No-Spill attaches to the hull using two super strong suction cups. Designed for use with gasoline or diesel fuel. Fits all boats with fuel tank vents up to 1.5" (3.8 cm) in diameter. Patented.