These liners are designed to notify consumers if their product has been tampered with. In addition, it features an FDA compliant pressure sensitive (PS) coat that seals to plastic or glass containers, securing product from contamination. Application is easy and no equipment is necessary! Simply twist tightly and allow a few hours for the adhesive to bind with bottle. Suggested product contact includes dry products like candy, spices and in some cases syrups. Not recommended for oil products. As always, we highly recommend testing your product with our closures!