The L327BK is a black PP plastic 28-410 smooth skirt disc top cap. Disc top caps are made of two pieces: the skirt and the disc. To dispense product, you press on one side of the disc, causing the opposite to snap up. You can then reverse the process to store product. This closure is commonly used for dispensing shampoo, lotion, conditioners, creams, and other personal care products. This lid is made of polypropylene (PP), which means it has a high heat tolerance level and an excellent resistance to fatigue. This closure fits a container with a 28-410 neck finish. The first number refers to the diameter of the container's opening (in mm). The second number refers to the thread/style/depth of the closure's skirt.