Corning Pyrex 99445-20 Borosilicate Glass Round Bottom 36mL Disposable Rimless Culture Tube, 20mm OD x 150mm Length, Clear (Case of 500) PYREX 70mL Reusable screw cap culture tube with a PTFE lined phenolic cap Caps fabricated from special formula resistant to effects of temperature and steam in autoclaving; glued-in - white rubber liner PTFEinterface firmly bonded to glued-in rubber liner provides sure and highly inert sealing face White enamel marking spot for pencil notations; pencil marks easily erased For replacement caps see part Number 9998