This is a replacement for the E Liquid Cartridge in the Suorin Air Starter Kit. These hole up to 2ml of product and are easy to refill. To refill this all you have to do is remove the plug from the filling hole and pour into it. There is a wick made of cotton to bring E Liquid from the chamber to the atomizer to be vaped. It is important to ensure metal connection points are kept clean for firing efficiency.