Working Voltage: DC 9V
Output Voltage: DC-3.5KV-10KV
Insulation Resistance:Source wire shell>=40mΩ
Dielectric intensity:Source wire shellAC 3000V 50Hz 5mA
Operating temperature: -10-50℃
Storage temperature:-20-50℃ 
Anion quantity:15million Pcs/cm3 at distance of 10cm
Power Requirements: 9V Battery

1.Do not insert Metal and other conductive material into the negative ion emission port

2.Do not use in explosive environments
3.Do not use in wet or raining environment
4.Keep away from food.
5.As to the two carbon brush head, do not touch to affect the releasing of negative ions.
6.Keep out of reach of children.

An interesting article on Negative Ions here http://americashauntedroadtrip.com/spotlight-on-negative-ions/