This seal is the original type seal which was used on the Spartan 2 piece windows which were used on most 1950-1955 Spartan trailers. It is made from premium silicone rubber so it will not harden, crack or shrink like the original seals do. The original seals must be removed from the window jambs. Care must be taken so that you do not damage the aluminum framing that holds the original seal. We typically go ahead and remove the window and the window hinge to make removing the old seals and installing the new seals much easier. The window hinge will need to be re-riveted to the window jamb once the new seal is installed.
If you do not want to go through the trouble of removing the hinge, we do offer alternative seals that can be used where removing the hinge is not necessary. Go the our part# CHW154 to view those seals and see photos of how this is done. This seal is sold by the foot. You will need to measure your windows to know how many feet of seal you will need.