I believe mine is a H3R FIRE EXTINGUISHER MODEL A344T--available from Aircraft Spruce, but much cheaper at SkyGeek. Mounted on the pilots side, next to the fuel cutoff valve. Installed a couple of nutplates on that coverplate panel, cut a few holes in the upholstery to match the nutplates, and mounted the holder over the upholstery. It requires that I remove the bracket when I need to get into the panel, but no big deal.