Hookah stem brushes are cleaning tools that help to clean the hookah stem, which can become clogged with residue over time. These brushes come in different sizes and shapes to fit various hookah models and can be made from materials such as bristle wire. It is important to clean the hookah stem regularly to ensure the best smoking experience and to prolong the life of the hookah. Hookah stem brushes are an essential accessory for any hookah user.