This 1000mL centrifuge bottle is made of transparent polycarbonate and has a polypropylene screw closure. It has a narrow-mouth design and excellent mechanical strength. For leakproof service at maximum rated speeds or when spinning hazardous materials a NALGENE sealing cap assembly (see item#: NAL-DS3132-0063) is required. Before autoclaving set closure on top of the bottle without engaging the threads. For proper performance this bottle must be filled to at least 80% of the total capacity. This 1000mL bottle has a maximum rating of 7,100 x g. Autoclavable. Capacity: 1000mL. Material: polycarbonate with polypropylene screw closure. Nalgene #: 3122-1000.