A home owner from Virginia says:
September 6, 2016
I need to replace the block and tackle balance on my MW single hung, tilt vinyl windows. I have attached pictures of the existing balance. The black block on the bottom of the balance is 1 1/4W x 1 1/2H The assemble length is 34 1/2 in. The only difference I really see is the way the sting fastens to the top of the window jam. My window has a clip that slides into the jamb and the picture of the 850 balance has a screw. If you could, please verify I am looking at the correct part before I place my order. I will be replacing these on 7 windows so I will need 14 balances. Thank you in advance. Henry
Tom from SWISCO responded:
September 8, 2016
Sure, we can definitely help. This old nylon piece is a hook that goes into a hole at the top. I'm afraid they're no longer made, and the balances you have are designed with metal screw tabs. We actually sell a screw plug, our 26-200, which fits into the same hole where the old nylon hook went. If you pop the 26-200 in that hole, you can install the modern style balances with the metal screw tabs.