Borosilicate glass stopper with hexagonal head for improved grip.Cone Size: 14/23Overall Height: 56mmGround glass stopper supplied in European 'B' length joint sizes making them suitable for use with any jointed glassware products with the same joint size. Ideally suited for use with Quickfit® jointed glassware and other glassware having ground glass joints.Complies to ISO 383 standard tapersBorosilicate glass for chemical durability and high temperature performanceHollow blown construction to reduce weightHexagonal head prevents the stopper from rolling and provides good gripTop of the stopper is flat allowing them to be stood on end and avoid contamination of the ground surface