Double hung window, lower sash

Thanks for writing in. This T-Lock Shoe looks like our 15-195. Go over the dimensions to ensure it matches what you have. As far as damage to the window track, I'm afraid there's not much you can do. You could try shaving sides of the shoe down so it glides more easily along the track, but you can't go overboard with this or else it'll be too loose in the channel. Let me know what you think.