Sci/Spec Premier Narrow Mouth Bottles are made of natural HDPE with a rigid polypropylene leakproof seal cap. These bottles are perfect for shipping liquid samples without the worry of any leaking during shipment. Our lab quality containers are available precleaned with Independent Laboratory analysis (3000 class) and without Independent Laboratory analysis (2000 class), as well as without the precleaned feature (1000 class). Sci/Spec Premier Narrow Mouth Bottles are washed to EPA Protocol "C".