Made by Honeywell this item is marked "Tank Unit-Fuel Quantity". NSN Stock number is 6680-00-573-8139 and Manufacturers part number is FG20251, Series 2. This item is about 23" long. It consists of 2 plastic tubes that are 18-1/2" long and 19" long by about 1" in diameter. There are two support brackets to keep them still. Attached to the longer tube is an aluminum housing with the above information on a tag. On the sides of the green cylinder are 4 male and 4 female connectors. Coming out from the bottom of the aluminum cylinder is a white and blue wire that attaches to the top of the smaller plastic tube. There are 8 mounting holes that are 1/4" in diameter. They are 1-3/8" apart measuring from center of each hole. Unused in original box.