The L2129BKH28 is a black PP plastic 24-410 smooth skirt disc top lid with universal heat induction seal (HIS) liner. Disc top lids 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 closure comes with a heat induction seal (HIS) liner, already placed inside the cap. An HIS liner is a metallic disk that provides an airtight, tamper-evident hermetic seal when an appropriate heat induction sealing process is applied. This liner can work with plastic or glass containers. For more information on heat induction sealing and available machinery, please read our article, How to use HIS liners and a heat induction sealing machine. 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 24-410 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. Please read 5 seals and how they make perfect liners for your container for more information on liner types.