GP-3003B1 hand held super scanner metal detector for check security  

Technical Specifications
Power Voltage:9V(6F22) standard or rechargeable battery
Power:270mW
Operate Frequency:22KHz
Operate Current:< 50mA
Operating Voltage:7V-9V
Operating temperature:-50°C to +55 °C
Net Weight:409g
Dimension:41(L) X 8.5(W) X 4.5(H)cm
Indicator:Visual: Red / Green LED 
Detecting way:Speaker or Earphone;(Earphone not included) , vibration 
Control:On/Off Switch; Low sensitivity Switch Sensitivity Adjuster

Performance:The sensitivity of the detector is determined primarily by the size, shape 

and composition of the object to be detected.

Maximum detection range:
Object                        low sensitivity           optimum sensitivity
38 caliber hand gun         15cm                        20cm
pen knife                      10cm                        15cm
Razor blade                    5cm                       10cm