These replacement shafts for magnetic impellers come in stainless steel, glass, and polysulfone (with thrust washers) and are for use in glass spinner flasks. Wilmad-LabGlass is a leading manufacturer of NMR and EPR sample tubes and accessories, a diverse line of Laboratory Glassware and Scientific Equipment, as well as Precision Engineered Glass, OEM Quartz components and assemblies. 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.