The Spin vaporizer pen offers a host of great features in an affordable package: Adjustable Voltage – The dial on the bottom of the pen allows you to adjust the voltage anywhere from 2.0 – 4.0 Volts. Charge Indicator – Know when your battery is running low before it’s out with the battery power indication light. Flex Connect™ – This connection system reduces issues with ground outs and sticky carts pulling the pen apart when removed. 400mAh Battery Preheat Mode