Caulkstrip is made with PVC and High quality butyl rubber guarantees.Smooth andenjoyable surface will never turn black,be mildew or break.With theanti-bacterium added,the environment-friendly material that ismildew-free,without poison,free from smell can protect people health.Can be usedfor a long period of 5 years,with a low cost per year.Self-adhesive,user-friendly and no tool needed.