Introducing The Ooze Vault Extract 510 Battery Mod + Storage Chamber | 450mAh, The Vault has a unique, flat shape that is essentially a cross between our stick-style batteries and palm-style batteries like the Duplex. It is tall and flat with rounded corners that is super comfortable to grip. The cartridge screws directly into the top on one side, extending straight up. The bottom features matching chrome knobs. One is marked with numbers that control the flex temp and allow you to select a voltage. There are three different light colors that indicate different voltage ranges. The other knob screws all the way off to reveal a secret compartment for storage! Keep an extra cart with you so you never run out, or pack the included wax atomizer with concentrates and take it to go. You can also leave it empty and store your single cartridge in there when you put it in your purse or backpack, to make sure your cartridge doesn’t get broken in your bag.