ITEM NAME:1X 150mm Air Regulator Gauge Spray Gun In-Line Water Oil Trap Filter Separ FHL.Size: 150mm. Air Pressure Regulator Gauge Spray Gun In-Line Water Oil Trap Filter Separator. It fits into your Airline or directly onto a Spray gun to prevent water contaminating paintwork. Product List: Mini Air Pressure Regulator 1, In-Line Water Trap Filter 1.