This is a Scuba Diving Tank -OR- an air supply tank for a B17 Gunner’s Ball Turret. I think that these started out as gunner’s air supply tanks, and were repurposed later for scuba diving. I have seen pics online of both applications. ^ However, this tanks is vintage millitaria, and is quite rare. None other is available anywhere that I can find. ^ I tested it with compressed air and it holds air fine with NO leaks. The threads at each end are good. One end fitting had the numbers T619239 on it. ^ The tank has a small dent in it. Unfortunately there was writing on one end that is now gone because of the flaking yellow paint. The tank itself is Aluminum. Check out the pics! ^ Check out our Feedback! Message us about any problem, and you will have our attention in a HURRY. It’s just that I don’t know what the cost will be, since I don’t know where my customer will live. ANYWAY– Just contact me and I can give you a DEAL. It works this way…. They also read all my messages. A WORD OF ADVICE. If you see something that you like and it is a price you can afford…. Because, while you are trying to carve a few pennies off of the price, someone else comes in and buys it at full price. I have seen this happen over and over again. Many of my items are very hard to find. ^ DOLLAR BILL: If you see a dollar bill in any of the photos it DOES NOT come included with the item. It is judge size and perspective only. DO YOU LIKE THIS STUFF? CHECK OUT OUR STORE! NO OTHER STORE IS LIKE OURS. YOU WILL BE SURPRISED AT THE VARIETY YOU WILL FIND THERE. If you like our service, do the same for us! Of course, if you order at any time from Friday noon through Sunday morning, there will probably be an extra day or two delay. ^ My Offer Policy: If you choose to make an offer on this item, here are some things you should know: I do not have time to play games with multiple offers. If I give you the same counter offer twice, that means that that is my bottom price FOR NOW. If you do not like the price on my item, wait a month! ^ About our store: We are a family business. Here is what we do: We procure your special items; we test and check them out as if we were going to use them ourselves. We pack it like we expect it to arrive safely at your doorstep, and we respond immediately to any problems you may have.