double hung tilt window bottom weather seal
A handy person from pittsburgh pa says:
May 12, 2016
this is a bottom seal on a double hung tilt window. it looks like a bubble seal of some type. the part above the bubble looks to be about a half inch and the bubble itself is about a half inch.
Paul from SWISCO responded:
May 13, 2016
It's hard to say. This is a pretty unique shape. See our 58-182 and carefully go over our dimensions. Could you use this as a substitute?