The Vertex Slim Variable Voltage 510 battery is a great vape battery for oil and e-liquid vapers. The Vertex Vape Pen features a 350mah capacity and variable voltage settings. Adjust your settings based on the type of eliquid or oil you are vaping. For higher end or ceramic cartridges you should adjust your voltage to at least 3.7 volts. The Vertex Vape Pen is designed for the beginner who is looking into vape products and wants something affordable, discreet and simple-to-use. This battery is one of the most slim batteries on the market.