A carb cap is a specialized accessory used in dabbing, which is a method of consuming concentrates like cannabis oils. It is placed on top of a banger or nail after the concentrate is heated and applied. The cap helps to trap heat and vapor, allowing for more efficient consumption and enhancing flavor. By restricting airflow, the carb cap creates a vacuum effect that helps to vaporize the concentrate at lower temperatures. This can lead to a smoother experience and better preservation of the terpenes, which are responsible for the flavor and aroma of the cannabis concentrate.