Digital vacuum gauge uses precision current source and solid state electronics for better resolution and accuracy than analog gauges. Does NOT use mercury. Large, easy-to-read display immune to parallax errors. No moving parts; resistant to dropping and rough handling. Inter-changeable tubes; head surfaces are nickel plated steel, ceramic and platinum alloy. Can withstand up to 30 psig max. Supplied with 10' sensor cable with 1/8" MNPT connection. Gauge includes tube and AC adapter. Operates at 120VAC.