Optifuel OH518K - Optimix Fuel 5% Nitro 5 LOptimix 5 Designed for engines requiring low Nitromethane content. 5% Nitromethane and 18% Synthetic Oil. Supplied in full 5L containers not US Gallon (3. 78L) Ideal for beginners and users who run low Nitromethane content engines. Content: 5L Optimix fuel with 5% Nitromethane & 18% Klotz Synthetic oil Optifuel is the product of extensive testing and development using the very latest onboard monitoring techniques to log operational flying parameters