Two Hole Gauge Adaptor 4AN or 6AN (Blue or black depending on what we have in stock) Swivel. Use this custom fitting for all gauges and nitrous bottle heater kits to mount the pressure switch. Comes in 4 or 6AN male fitting with male and female on opposite ends. The two ports are 1/8"npt female. Comes with one hole plug just in case you only need one port. Another dynotune innovation.