Milestone single hung series 1000 channel balance replacmentS

Hello there. I'm confident we can help, but that stamp is not an identifier. It just tells us the strength of the channel balance. To know what balance you need, we'll need you to remove the old one and show us clear photos of the attachments on both ends of the metal channel. We should be able to narrow down your needs from there. 

Thanks for your photos. Based on what I see here, you have either our S380-29 or S385-29, depending on the depth of the bottom shoe. That's the only difference between them. I recommend measuring your shoe and referring to our dimensions to confirm the best match.

Your old stamp of "28F" uses an older rating system, but our options should be equivalent. In this case I believe our match is the 2860, but you can always weigh your sash to verify. Two balances with a 2860 stamp can hold a sash weighing 32 through 35 pounds. As long as yours falls in that range then you should be A-OK.

Comparison of the S378, S380 and S385 balance shoes.