This is what information i pulled up on the internet about these fiberglass tanks. These ones are outdated but can be filled at the reservations. There are 3 tanks selling at $35 Each Firm cash deal. There good for boats and camping.
Ragusa Cylinders are built with safety as the first priority. Lighter than aluminum and steel, this propane tank is made of a rugged, non-corrosive three-layer composite that was built with optimum safety in mind. It features a one-piece seamless inner layer and a visible gas level. Ergonomic handles make it easy to carry and stack. Has a QCC thread-on valve for QCC and POL connections. 17lb. capacity (4.7 gal.), 18-1/8"H x 12-1/2"W. Empty Weight: 10.3lbs.