Showers and bathtubs usually contain strips that clip onto the shower glass to prevent water leakage. These strips are typically made from a heavy plastic such as PVC and are available in many different colors and styles. Mounting them to the glass is easy; all you have to do is push the strip firmly onto the edge of the glass to create a seal. Before you can mount these strips, you must trim them to the appropriate length.
Place the strip on a flat surface and position it so the end you need to cut hangs slightly off the surface.