This seal installs first on the body then the glass is placed in the opening. A separate lockstrip (Not Included) inserts into the rubber and secures the glass in place. The part numbers for Lockstrip are Chrome LS 3-C and Black LS 2-A. This product is made from the original specs and with high quality ozone resistant EPDM rubber for a great fit and long life. This item is designed to be installed during glass replacement.