Millard widow sash spring balancer?
A quick learner from Shingle springs , ca says:
May 20, 2015
Looking for two spring loaded Millard sash balance. Metal housing is 21 in long and about 1/2 in wide
Paul from SWISCO responded:
May 22, 2015
Based on your pictures, I think our S385-21 channel balance is a close match. Just confirm that the nylon attachments on either end are the same size. I would also recommend our 2040 option.