Translucent fiberglass propane cylinders allow easy inspection of the remaining fuel level. Up to 30% lighter than steel these seamless composite tanks meet all DOT, TC and ISO specifications. Seamless, woven inner vessel utilizes Derakane™ epoxy vinyl ester resins and E-Glass fibers to achieve a tensile strength in excess of 200,000lbs. Durable polypropylene copolymer outer carrying case eases handling and protects the UL-listed Type 1 OPD valve during transport and installation. Compact, flat-bottom assembly is stackable, fits conventional propane lockers and since it can never rust, will not leave rust stains at site of installation. Three-year warranty. 17lb.