Used propane tanks. The silver horizontal tank is 130 gallons. The two small ones are bbq grill tanks. They have propane In them. The upright tanks are 30 gallons and 20 gallons. The red one is 75 or 80 gallons. The horizontal smaller silver one is 30 gallons.  The sizes are approximately only. I could not find a size stamped on them except for the silver horizontal. They do not leak and are in good condition. However I would upgrade the valves. Price is negotiable as long as it is within reason. I can load them with a forklift with no charge for loading. More information upon request.