The head retention drinking glass. The Headmaster captures the natural carbon dioxide in the beer at the base of the glass. It is gradually released during consumption to serve up the creamiest beer and retain the head until the last mouthful. It is designed to continually revive and strengthen your beer head whilst you drink. Pack of 6 **Please note that due to the volume of breakages we are unable to supply this product online. These items can be purchased in-store only.