The Day Pen is a 350mAh slim pen battery that takes quality and the user experience into careful consideration. With only a twist of the temperature control on the bottom, the user can choose their heat setting preference from as low as 2.0v, all the way up to 4.0v, and anything in between! No clicks, No worries! The Day Pen also features a Preheat function that will ensure the perfect hit, no matter how thick the oil in your cartridge is. Just press the button twice to activate the preheat setting before you go in to puff. Designed to be compatible with any 510 thread cartridge, the Day Pen comes with a USB compatible charger that easily twists directly onto the 510 thread. The Day Pen is aptly named because its charge is just about guaranteed to last you a full day’s worth of use!

Volume: 350 mAh
Length: 95mm
Diameter: 11.2mm
Weight: 22g
Voltage: 2.0v - 4.0v
Preheating output: 1.8v

Bottom knob adjustable for voltage from 2.0v - 4.0v
Smart chip inside