Thanks for replying. The length of the metal channel is 33 inches without the plastic attachments.
The bottom shoe is 1-1/8" deep.
Thank you for your reply. The window weighs 21 lbs, which is within the 18-23lb range of the 3230 option. Since the 3240 starts at 23lbs, I suspect the 3230 is the correct option.
Thank you for your help,
Mike