Identify Channel Balance

Thanks for posting, John. Based on the fittings at both ends of the metal channel, this looks like either a Series 380 or Series 385 Channel Balance. The only difference between these two balances is the depth of the bottom nylon fitting, or 'shoe'. The depth can be thought of as the measurement from the shoe's 'heel' to its 'toe'. See the diagram below for reference. Measure the depth of your old balances' shoes to see which Series matches best. While this is probably the case, please be certain the balances from each window have the same end attachments.

Comparison of the S378, S380 and S385 balance shoes.

Once you know what Series you are working with, it's on to choosing a length. Make sure you are measuring just the metal channel to determine this; do not include the end fittings in that measurement. Finally, you have to choose a stamp option, which designates the strength of the balance. Look for stamps on the old balances that denote this. If there are no stamps, or you are uncertain, weigh each window sash that the channel balances support. You can then match the exact weight with one of the weight ranges listed alongside each stamp option under the product description on every balance's shop page. Let me know if you have further questions. 

Thanks for getting back to us. This appears to be the same specifications you submitted on your previous post back on Saturday. Were you able to determine which of the two Series was the better match? If you haven't already, that should be your next step.

Once you've selected the right Series, you can follow the steps provided on that store page to make the proper selection as per your balance size and sash weights.