Aprox 1 1/4" wide 2" high 9/16" deep

If the thickness of the housing is indeed 9/16", you might need our Series 161 assemblies; just double-check the measurements to be certain! You then have to choose the correct spring weight. Unfortunately, your stamp presents a question as old as time: is it a 6 or 9? Ultimately you should weigh the window sash. Give us that exact weight, confirm the measurements as I explained, and we'll work out what you need.