0-15 PSI Low Pressure Gauge. Glow in the Dark Analog Gauge. High Quality Brass Components. Solid Brass Precision Movement with Bronze Bourdon Tube. Bourdon Tube movement is not affected by changes in temperature, humidity, or altitude. Molded Rubber Cover to help protect gauge. Chuck Rotates 360 Degrees for Easy Positioning. Pressure Release Air-Down Valve for Easy Adjustments.