I built my own output manifold for my compressor. I drilled and tapped holes in the manifold for over pressure safety valve, pressure sensing switch, a pressure meter and a male foster fitting like the ones found on air gun tanks. This allows me to use the same whip I use to charge my guns to charge my 12 liter bottles. Please note that the air flows in the opposite direction as the foster fitting was intended to do. Most male foster fittings have a check valve internally that will prevent that reverse flow. So, to solve that issue, use a small pin punch and simply knock out the internal plug. In this application, once the bottle is full, you can shut off the bottle valve and bleed down the whip and compressor with the release valve on the fill whip.in the same manner as you do an air gun after filling.