The same procedure is used on the window vent frames. First the rubber bedding is shaped into a "U" and laid into the channel. Next, the glass is gently seated, and the excess rubber is trimmed away with a razor. You must be careful when seating both the window and vent glass because any hard contact with on the edge could cause it to shatter. Here, the technician has a rubber mallet on hand to persuade things to go together.