Replace part number

Hello! I need you to check some details before we proceed. Measure the length of the metal channel, and only the metal channel (no plastic attachments). It would be highly unusual for a 21" balance to be marked "27 4". In light of this, you should also remove your window sash and weigh it. The weight will confirm the stamp option.

Once you confirm the length and stamp option, you need to narrow down the Series of the balance. It's either Series 380 or it's Series 385, but you need to measure to figure it out. If it's 1-3/32", as below, it's the Series 385. If it measures 1", that's the Series 380.