Sterile polypropylene containers are manufactured from medical grade plastic, which ensures consistent quality and performance. Optically clear, flexible, and resists breakage. This container is ideal for use in harsh transport conditions or in pneumatic tube systems. There are graduation markings on three sides. The streamlined straight-sided vials are stable, stackable, and save space in storage. Color coded orange “O-ring” cap, designed to grip the top and sides of the vial. The vial fits into the groove of the cap for additional contact and a better seal.