Atlas PTFE stirrers have steel shafts for strength and a thick PTFE coating for chemical resistance.  The Atlas glass stirrers are cut to length by Syrris before shipment (please specify reaction vessel and desired stirring height from the bottom of the vessel when placing an order). Glass stirrers are required for work under vacuum.  All Atlas Stirrers are compatible with the stirrer seal and guide (2101011).  Custom profile stirrers are available on request.