These Drosophila bottles, precision moulded from pure vigin medical grade polypropylene, are reusable yet disposably priced with thin walls for flexibility. Bottle openings are designed to accept standard size paper lids, foam plugs, cotton balls, and Flugs. The 8oz round bottom bottle has an indent on the bottom for securing food.These bottles are made with autoclavable polypropylene and are designed with thin walls and graduation marks. This item is equivalent to Fisher part AS-117.