The L1160WHH28 is a white smooth child-resistant lid made of polypropylene (PP). This lid has a very typical child-resistant look and feel, making this lid ideal for packaging pills or other potentially hazardous products. The lid will fit containers with an 89-400 neck finish and includes 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. 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.