The Cartisan Black Box is easily one of our favorite 510 cartridge batteries for many reasons. The first reason we love it so much is its massive battery! While this vape is small enough to conceal in your hand, hidden inside is a 900mAh battery which will let you vape for days in between charges. Next, with 3 adjustable heat settings to choose from you can fine-tune your hit with ease to get the best results out of different carts. It also has a super wide 11.5mm opening to fit almost any cartridge you might get, and comes with all the accessories you need to make a smaller cartridge fit just as well. Finally, this unit is crazy durable and even protects your cartridge from breaking, which is one of the biggest reasons so many people prefer the Black Box compared to normal pen batteries.