Brian, I'm not sure, it appeard one day a couple of weeks ago on one of the construction crews' trucks. It had not been 'adapted' for the suction hoses we use to drop liners, so I gave them the 'box style' one we'd been using in exchange, which was ready to do liner drops. I'll try to remember to ask where it came from and see if I can't get a look at the manual for it(7 am isn't the time to get the 'best results' out of my brain ). If I can get the manual, I'll copy the pertinent info and let you know.