This C576-20MA uses a different tamper evident concept when compared to the C575 Series. No locking tab is necessary when the tamper evident feature is used. Simply screw the cap on the container and the tamper evident sealing ring is automatically locked in place. When unscrewed, the ring is detached from the cap, showing clearly that the container was opened. Also designed for Collection, transport and storage of specimens, the polypropylene containers are safe to use even in adverse conditions. Containers are uniquely stackable, shatter resistant and are manufactured from virgin, polypropylene. These straight sided containers are available in many sizes from 20 to 120 ml. Non sterile. Containers and caps packaged separately in bags of 100.