The J249WH is a 6 oz white HDPE plastic single wall jar with 63-485 neck finish. Single wall jars are normal 1-piece jars. They're called "single wall jars" to distinguish them from the 2-piece double wall jars. This jar is made of high density polyethylene (HDPE). HDPE has a strong tensile strength, good impact-resistance and chemical resistance. It is highly rigid and highly resistance to scratches and scuffing. This jar is typically used for powders, drink mixes, supplements, pills, capsules, and other health supplemental products. This jar has a 63-485 neck finish, and will fit closures with the same finish. The first number is the diameter of the container's opening (in mm). The second number refers to the thread/style/depth of the closure's skirt.