Purchased 120 ml and 600 ml. Used as a chamber for washing accessories. Those with large capacity, the inner lid is rigid, and its knobs are poor. I am worried that I can not pick up the knob while using it. Things with a small capacity, there is no discomfort. Transparency is also sufficient. Because it is polypropylene, although it can withstand most organic solvents, it seems easy to scratch, so careful depending on the application.