Allentare Black 40PSI Mechanical Water Pressure Gauge Black Bezel. Allentare marine gauges provide an ideal, cost effective solution for new boats or drop-in replacement gauge for older boats. Allentare gauges are designed to work with most commonly found marine senders and wiring harnesses used today. Features Connection M4 Stud. Input Type Mechanical. Mounting Hardware Included. Voltage 12V. Diameter 2-1/16 . Diameter Metric 52mm. Max Range Outer Scale 40 PSI Allentare marine gauges provide an ideal, cost effective solution for new boats or drop-in replaceme Connection M4 Stud. Input Type Mechanical Mounting Hardware Included. Voltage 12V Diameter 2-1/16 . Diameter Metric 52mm Max Range Outer Scale 40 PSI