Borosilicate glass with one graduation mark. Fitted with chemical resistance polyethylene stopper. As per DIN ISO 1042 standard. White Graduation. Cap. 5 ml, Socket size 10/19, Tolerance ±0.025 ml Calibrated to contain. NOTE: Polyethylene stoppers cannot be autoclaved. They have a temperature compatibility range of -40°C to +80°C. Remove stoppers before autoclaving the glass flask body.