11lb Vertical Fiberglass Composite LPG Cylinder with Type 1 Valve - OPD, DOT, TC ApprovedThis composite propane tank has an internal bladder encased in fiberglass, which allows users to see the gas level. The propane construction also means this cylinder is lighter than a standard steel cylinder.Features:Non-corrosive 3-layer fiberglass composite cylindricalErgonomic collar for a nice lookThe handle makes it easier to carryType 1 valveFrequent Questions:Where can they be refilled?These cylinders are DOT-approved for the USA, as well as TC-approved for Canada, and can be filled at any reputable refilling station.How safe are these cylinders?These LPG cylinders are designed with safety in mind. They started with the boss and blown-molded polypropylene internal bladder, and then the outer winding of fiberglass to ensure a tough finish. Then it is encased in a UV-protected outer casing that allows for light to pass through so that you can see how much propane is left in the cylinder. "Safest on the market.”When do they need to be recertified?Your cylinder needs to be re-qualified every 5 years via an external visual inspection by an approved re-qualifier. As per TC and DOT, the valve does not need to be removed for inspection or replaced here.How long is the useful life of the cylinder?Currently, the useful life is 15 years from the date of manufacture, and the service life is determined by DOT and TC.Will cylinders work in cold climates?The cylinders are tested and approved down to -40°F/C. However, the use of LPG in low temperatures is limited by the vaporization capability of the specific LPG mix.Will the cylinders work in warm climates?The cylinders are designed to withstand temperatures well above 149°F (65°C), and users who live in hot climates report that the design holds up well to regular use in steamy temperatures.