We bought the
58-183 T slot offset hollow foam seal to replace the aged damaged ones in our Simonton windows. After a little learning curve, these were easy and quick to install. I raised the bottom window by half, pushed up the right side so that side can be disengaged from the frame, pulled it forward a few inches so the "T" track can be accessed. The new T slot foam seal slid in easily then put the window back in. Suggestion: The new seal comes in a circle and is difficult to make it stay straight, so measure twice and cut once.