This Pfeiffer Vacuum DN 250 ISO-F Mounting Kit for HiPace 1500 and 2300 Turbo Pumps has a multifunctional coating for anti-twist protection. It is used to filter the vacuum flow and keep objects from being sucked into the HiPace 1500 or 2300 turbo pumps. This screen has an ISO-K/F 250 flange size. Depending on the gas used, some pump speed reduction will occur when using this screen. This screen centering ring has Pfeiffer part number : PM 016 482 -T.