Material: DURAN ® glass borosilicate glass 3.3, PP screw closure with PTFE membrane. Autoclavable: yes. With membrane screw cap and pouring ring. Four baffles on the base create a turbulent flow, enlarge the gas exchange surface area and therefore increase oxygen intake. Automated production ensures a reproducible flask geometry and consistent results. Double-thickness walls for exceptional mechanical stability With retrace code (batch identification) Easy-to-read scale with graduation marks for assessing the content Baked-on, highly resistant white print Temperature-stable up to +140 °C Baffled flasks DURAN ® with screw closure