window balance replacement

Question

I'm ordering some non-tilt window balance replacements. I have a question before ordering, what is the difference between the s380 and the s385 series? I know mine is 29" block & tackle balance. my problem is I can't accurately ID the ends or guides. The only marking I see on my original balances are 29A. Any help is greatly appreciated. Thanks Todd

Bob · Accepted Answer

The difference between the Series 380 and Series 385 is the depth of the bottom nylon shoe, or the 'heel-to-toe' measurement. The image below shows the difference. The Series 380 has a shoe depth of 1", while the Series 385 shoe is 1-3/32" deep.

Comparison of the S378, S380 and S385 balance shoes.