These test tubes are graduated and self standing. 3mL polystyrene and 12mL Polypropylene options are available. These flat bottom, self-standing tubes are available in clear polystyrene (PS) or unbreakable polypropylene (PP). The 3mL polystyrene tubes measure 12 x 57mm. They are graduated with rim. The 12mL polypropylene tubes measure 16 x 92.5mm. They are non-graduated, without rim.