SIMCO FMX-004 Electrostatic Field Meter (0 ~ ± 1.49kv, ± 1kV ~ ± 30KV)

Display Features :  Push button POWER, HOLD, ZERO and MODE
Read Out Bar graph- red LCD for positive polarity voltage; blue LCD for negative polarity voltage; battery capacity and error display indicators
Measurement Capacity AUTO: 0 - ±1.49 kV (low range); ±1.0 kV to ±30.0 kV (hi range)
HI Range: 0 - ±30.0 kV
LOW Range: 0 - ±3.00 kV
Ion Balance: 0 - ±300V
Measuring Distance 1" ± 1/64" (25mm ± 0.5mm); LEDs guide for correct distance (between charged object and fieldmeter)
Power 9 V, 6F22Y manganese battery

Datasheet