Safe-T-LockTM sample vials one of the few air-tight, leak-proof, snap cap vials on the market. They are ideal for all types of sampling and storage needs in the food, dairy, cosmetics, petroleum and environmental industries. They are manufactured of virgin polypropylene for increased durability and reduced chances of breakage. The etched cap provides a large marking area for identification. Graduated in ounces and milliliters for approximate volume estimation. Vials are also sterile and rNase/ dNase-free.