GEM Biodiesel Cube is 100% pure biodiesel made from canola oil (better than soybean oil). Can be used as a fuel or an additive. Can be mixed in any proportion in diesel fuel or it can be used by itself. Use in any diesel engine or lamp (with preheat). The container holds 5-gallons and can be refilled. No need to vent this package as the internal bladder will collapse as the product is removed. We will provide you with one valve that can be used on all cubes. You may provide a 3/8 inch hose with the valve. Valves can be ordered separately.