Product HighlightsExtremely high quality pressure gauges, liquid filled for extended service life and shock resistanceRanges available from vacuum to 15,000 psi1/4" NPT Center BottomLightweight shatter-resistant ABS, Plexiglass™ lens for extra strengthUnique o-ring case and connection seals guard against leakage and protect against shock and vibrationRelief disc on top or back provides positive case reliefBrass and copper alloy movementHigh grade Glycerine fill dampens the effects of pulsation, vibration and shock loads, and provides lubrication of the movementVolume oriented