Sorry it's actually 5/8" wide on the open side and 1/2" on the back side. This is for a non-tilt window.
Thanks!
Paul from SWISCO responded:
December 2, 2016
Take a look at our Series 390 to start out. This comes with our 19-002 top and 15-001 bottom, so if these pieces match what's on your own balance I think it will work out.