I recently replaced my Andersen wood double hungwindows dating from 1977 and was able to salvage a few of the original sashbalances. Thesecame from windows measured by visible glass of approximately 23 15/16” x 32 7/16”. I could not find replacement part numbers on the balancers but there are‘codes’ that may be able to be cross referenced by calling Andersen or byvisiting their web site. There are 2 of K14 10#31 12...-77 (12-77 is likely December of 1977) Each weighs15.9 ounces and they physically measure 6 1/4" x 2 3/4" x 3/4". Thanks for Looking and Iship fast with tracking and insurance.