A boss head, also known as a boss clamp or laboratory clamp, is a type of laboratory equipment used to hold and secure glassware and other laboratory apparatus in place during experiments. The boss head consists of a clamping mechanism and a screw, which is used to tighten the clamp onto a rod or support stand.

The clamping mechanism typically has a serrated surface or jaws that grip the glassware securely, while the screw is used to adjust the pressure and keep the apparatus in place. Boss heads are made of materials such as aluminum, stainless steel, or plastic, and are available in various sizes and designs to accommodate different types of glassware and apparatus.

They are commonly used in chemistry, biology, and other laboratory settings, and are an essential tool for conducting accurate and precise experiments.