Description It has a Micro USB charge port at the bottom.The slim pen battery is designed to utilize 510 cartridges.The voltage can be switched with three quick clicks on the button and the led light will change the color according to the voltage red – 2.8V, green – 3.3V and blue – 3.8V. Five clicks will turn on or off the battery. The iKrusher Slim Pen battery can be charged through Micro-USB port on the bottom at 5V/0.5A. The battery has low-voltage, short-circuit and overcharge protection. Connect: 510 Thread Dimension:10*92.7mm Capacity: 290mAh Output Voltage: 2.8V – 3.3V – 3.8V 3-Clicks: Voltage Switch 5-Clicks: On/Off Switch Atomizer Protection Short Circuit Protection Low Voltage Protection Overcharge Protection Color: silver,black,purle,red,green,blue,white,more…   Included: 1* ab1004 cbd battery with A grade battery cell 1* USB charger cable 1* Blister packaging   Logo printed welcome,more details please contact us any time.