Ultra-Vacuum stirrer bearing for applications up to 0.6 Torr. Non-shedding bearing is manufactured from PTFE, Rulon and PEEK materials. Equally good in both vacuum and pressure applications as low as 0.6 Torr. Rated for up to 400 rpm with both glass (polished rather than precision ground is best) and stainless steel shafts of 10, 19 and 28mm diameter.