In general, vape pens can use a variety of plant-based materials, including tobacco, herbs, essential oils, CBD, and cannabis – but G Pen products are specifically meant for the latter. These materials can come in a variety of formats. These include liquids and oils – which typically come in a cartridge for easy application – and dry herbs, often called ground materials or flower. Another common vape pen material is a concentrate. A concentrate can be an all-encompassing term for waxes or dabs, and can also refer to liquids and oils, as they feature a concentrated amount of material to vape.