Meller Sapphire Centrifuge Cell Windows are designed for Beckman and other high-speed centrifuges and incorporate a scribed arrow on the edges to project the optic axis and simplify installation alignment. Optically clear and mechanically robust, these high precision windows resist etching, fogging, or degradation, as well as extreme centrifugal forces.Featuring tight tolerances to ensure proper sealing and alignment in the centrifuge cells, Meller Sapphire Centrifuge Cell Windows measure 19.03 mm dia. ±0.03 mm by 5 mm thick ±0.10 mm and are offered plano; with chamfers 0.35 mm x 45 degrees in two places, and have a 30-10 scratch-dig surface finish. Suitable for OEMs and end-users, custom sizes also offered.