ITEM NAME:Metal 1/4 NPT 2.3in Face 6 Bar Air Compressor Hydraulic Pressure Gauge #gib Store Home Promotion Hot Item Add to Fav.One new 0-6 Bar back mount water pressure gauge. This gauge features a 2.3" face and has 1/4" Male NPT thread on the back center of the gauge. 1/4" Male NPT Pipe Threads. 1 x Air Compressor Pressure / Hydraulic Gauge.