The larger sized unit is similar to a pen, but the main difference is that it has a larger heating element and larger heating chamber. The larger chambers allow the pen to produce more vapor, and to heat it up more quickly and efficiently than other devices. Most units will have a power button on the side or back, which allows the user to activate the device by pressing the power button for about a minute or so wholesale vape mods. This button allows the person using the device to start inhaling and creating vapor wherever they want, without turning on the power button. Each vaporizer pen is powered by a high quality battery, and each of the devices will produce approximately the same amount of vapor for the price that they cost.