This is a variable volt 510 mod that runs on 2 Lithium Ion 10440 3.7v batteries. The voltage is adjustable by a thumb wheel on the device. You can dial a voltage anywhere between 0 and 6.5 volts. No screwdriver needed. Dial to 0 to put in your pocket or purse. This device is small about the size of a Bic lighter. The mod does not come with an atomizer, batteries, or charger. High drain batteries are recommended for all Variable Voltage mods sold here.  There is a $3 charge for black and a $5 charge for pink or purple. There is a 7 day wait for the Little Sister Variable Volt mod.