Nalgene 3138-0050 Polycarbonate 50mL Oak Ridge Centrifuge Tube with Sealing Cap, PP/Silicone Gasket, Translucent (Pack of 10) Centrifuge bottle used with centrifuge equipment and for applications that require a durable container Polycarbonate body resists oils, greases, detergents, most inorganic acids, and impact over a wide temperature range, and is translucent for reduced light filtration while still allowing visual fluid monitoring Cylindrical shape for a wide variety of applications that require solution containment Polypropylene screw cap with a silicone gasket secures contents to help prevent spills and evaporation Sealing cap closure assembly included to secure hazardous contents at speeds of 10,000 x g RCF or greater