Window channel ID

Thanks for posting. If you are absolutely certain the longer balances are otherwise identical to the Series 380 balances you've previously bought, you likely need the S380-30. You'll need to look for a stamp on the old balances to determine what stamp option to select; or, weigh the window sash and go by the chart under the S380-30 product description to determine which stamp to pick. If you're not entirely sure the Series 380 is what you need, please send us photos of the fittings on both ends of the metal channel, and we'd be happy to verify.

Thanks! I agree, this looks to be a match for our S380-30. Your old stamp of 29C usually corresponds to our 2930 stamp option, but you can always weigh your sash on a scale to confirm. We have a char ton the S380-30 store page that tells you exactly how much weight each option supports.