Glass stirrer shaft (one-piece reactors, 250/500/1000 mL) Glass stirrer shaft (one-piece reactor, 400 mL) Glass stirrer shaft (one-piece reactors, 50/100 mL) Pitched-blade stirrer (downward, four impellers, 45°, for 500/1000 mL OptiMax reactors) Pitched-blade stirrer (upward, four impellers, 45°, for 500/1000 mL OptiMax reactors) Anchor stirrer (for 400 mL EasyMax reactor) Pitched-blade stirrer (downward, three impellers, 45°, for 400 mL EasyMax reactor) Pitched-blade stirrer (upward, three impellers, 45°, for 400 mL EasyMax reactor) Pitched-blade stirrer (downward, four impellers, 45°, for 250 mL OptiMax reactor) Pitched-blade stirrer (upward, four impellers, 45°, for 250 mL OptiMax reactor)