Tapox Tank Sealant. Designed to withstand 100% ethanol fuel. Most tank sealers used in steel motorcycle tanks are not ethanol proof, when they meet 5%-10% ethanol which is now present in most pump fuels, and they start to collapse blocking filters and carburetors. Tapox has a proven track record even when used with 100% ethanol fuels. Each pack includes sealant and activator, which when mixed should provide effective protection for a 3.5 gallon tank. Not suitable for fibre glass tanks.