This is a 3 sided aluminum window frame which will fit most 1947-1953 Spartan trailers. The size is approximately 33" wide and 17-3/8" high. NOTE - It does not have the top extrusion which slides into the hinge on the trailer. You will need to have that extrusion from your old window for this to work. The original Marvel windows which were made of steel are famous for rusting out on the bottom. Typically, the top extrusion of the window is still in usable shape. This 3 sided window frame was reproduced from the original Marvel brand window. This window frame does not come with the glass, or any of the seals but we do have the seals available on our parts e-store. You will need 8 foot of our part# CHW015 glazing, which is for 3/16 inch to 7/32 inch thick glass which can be purchased at your local glass shop. The glass will need to have the 2 bottom corners rounded a little so that it will fit properly in the new aluminum frame. You will need 6 foot of our part# CHW092 outer seal, then we always add up to 9 foot of our part# CHW017 on the inner window jamb. Adding this seal will help prevent the window leaks that are very common on these rear windows. Note, the display photo shows the entire window with glass & seals installed on a 1951 Spartan Imperial Mansion. If you want to make your own, we do sell the aluminum extrusion only also. Here is the direct link to the Marvel aluminum extrusion only: CHW153.