These borosilicate glass condensers have a double wall with interior spiral coil for efficient cooling. As vapors rise, they are condensed on the jacket inner wall and the outer surface of the coil. Top and bottom Standard Taper joints are the same size. Scientists rely on the expertise and artistic skills of Wilmad-LabGlass' engineers and glass specialists to manufacture NMR and EPR consumables and laboratory glassware of the highest quality. Used daily in academia, healthcare and chemical, petroleum and other industrial applications, Wilmad offers 7000+ items as part of their standard catalog as well as custom fabrication for individual glassware, glass repair services and OEM glass parts.