The carb cap is used to create a uniform temp within the surface area of the nail surface to evenly vaporize your essential oils. The point of using a Titanium Carb Cap is to obtain full vaporization at the lowest temperatures possible. The single hole around the edge of the cap creates a regulated influx of air pointed at the moat of the nail. This regulation helps spread and thin your material on the nail. Smothering your material in this manner prevents pooling or puddling and also has an astound effect on flavor. The cap also helps by providing insulation as well as protection from the wind for outdoor applications. The top of the Titanium Carb Cap has been tapped so that you may attach any different Shafts. Many people don’t understand that aromatic distribution on a nail while it is red hot is not the most effective, flavorful, or proper way to practice aromatherapy which will destroy the natural scent and aromatic compounds of your natural essential oils. When the nail is cooling from being red hot, once the color change goes from red to its basic hue, that when you want to drop your aromatic distribution on the nail surface and allow it to pool or puddle up. Placing the carb cap over the titanium nail head will create a heated dome to vaporize the pool at the temp and speed it should be to achieve the best flavor and effectiveness. Get your titanium carb cap and see what all the fuss is about.