NOTE: This product has no reverse connection protection, the input polarity cannot be reversed, otherwise the product is permanently damaged and cannot be repaired. Application: Assist to measure Micro-USB cable good or not. Assist to measure Type-C cable good or not. Assist to measure output current capacity of charger good or not. The usage of large batch ageing test at the charger factory. "SET" button:press "SET" to switch display status, Press and hold the button to set the load output recovery mode after protection removed. "ON/OFF" button: press the button to open or close output. Press and hold the button to set the boot default status of open or close. NOTE: Please check the output current of power bank carefully. The current of the general power bank is generally small, so adjust smaller current when the load was used. Specifications: Product Model: LD25 Rated operational voltage: DC4-25.0V Max discharging power: 25W / 35W Rated operational current: 0.25-4.00A / 5.00A (when fan don't work, the minimum constant current is 0.05A ) Fan Speed: Oil bearing intelligent temperature control fan,speed 580010%RPM(LD 25) Working temperature: -10-40 degC Adjustable potentiometer: Precision multiloop adjustable potentiometer Display mode: 4 bit LED tube Expansion port: Micro-USB port,Type-C port Product Brief Introduction: Micro-USB port:MAX current 2A USB male port (widened power wire,MAX current 5A) Type-C port:MAX current 4A Due to different batches, the words and pictures on the center label may be different, but it will not affect the use Color: black Material: ABS Package Contents: 1 x adjustable resistor Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.