stirring shaft can be used for 500 ml, 1000 ml and 2000 ml DURAN® GSL 80® laboratory bottles and can be driven with standard magnetic stirrers. Screw Cap • White, PSU, Cap liner Screw Cap • Blue, PP, Linerless Pouring Ring • Blue, PP Pouring Ring • White, PTFE Screw Cap Membrane Vented • Blue, PP