The Leaf Buddi U-Key Box V Pro Key Fob Vape features a unique “key-fob” shaped battery design that is intended to be lightweight and discreetly fit in the palm of your hand. The U-Key Box V Pro has a built-in, hidden, retractable 510 connector that is spring loaded and released with the press of the button located on the side of the device. With a built-in 350mAh battery the U-Key Box is compatible with most 510 cartridges. A compartment is incorporated in the side of the device to store your 510 cartridges when you are not using them, making this device perfect for those trying to conceal their oil vape. The U-Key Box V Pro offers three different voltage settings, which are 3.6V, 3.8V, and 4.0V which may be changed with 3 clicks of the fire button. The 15 second preheat function may be activated with 2 clicks of the fire button. The U-Key Box V Pro may be charged via the included micro USB Cable and the Micro USB port located at the top of the device. Overall the U-Key Box V Pro by Leaf Buddi promises to be one of the best conceal style 510 batteries on the market.