My Window balance 18" length

Question

Hi,

I have attached photos of my window balance, the length of the rod is 18". most of my windows are 36x36. I think it is a series 350 but I'm not positive about the shoe. Besides etched marking it is also marked in ink as follwos: UNIQUE 17-C-30 02/17/97

Q. how many balances should I have per window, is it one or two? I only have one on one side, please let me know if that is correct. Also let me know which part to order. Thank you very much, hope to hear from you soon. You may also reach me by phone or text at 305-498-1617

Tom · Accepted Answer

Hello! I agree, our S350-18 looks like a great match for your original. I can also confirm that you need two balances per sash; that would be one on each side. A window can't function properly with only one balance per sash. There are no exceptions to that rule to my knowledge.