Window Balance sash guide
A handy person from Florida says:
March 30, 2012
Attached are two profiles from the piece that attaches to the window. This accompanies a 1/2" 28c channel (non Tilt). Please let me know what part number to purchase.
Mike from SWISCO responded:
April 2, 2012
Thanks for posting on the discussion board.
Start by taking a look at the 18-110 Top Sash Guide, Seasonall.