Ideal for pharmaceutical or similar packaging, these water-clear polypropylene bottles are Boston round in style and molded from FDA compliant material. Matched polypropylene caps have a valve-seal design for a perfect, leakproof fit. Deep square threads withstand vibration and help prevent closure back-off during shipping. Ribbed caps are designed for torque-closure and easy opening. Inner bottle surfaces are smooth and rounded for easy cleaning and thorough emptying. Underside of bottle lists volume, material and includes an indexing notch. Recycling codes listed on 500 and 1000mL bottles. A protruding ring under the cap holds shrink wrapping securely in place. Autoclavable at 121°C (250°F). Do not autoclave with caps in place.