cmc 29 2ft 4

Thanks for posting. I'm confident we can help, but that stamp is not an identifier. It just tells us the strength of the balance. Please remove the channel balance from the window and show us clear pictures of the attachments on the top and bottom of the window track. The style of attachments used determines the type of balance you have. For the Top Sash Guide, we will also need to see clear pictures of its front and side, removed from the window. We'll do our best to aid you from there.

Thanks for getting back with the photos. I believe this is either an S380-30 or S385-30 Channel Balance. The only difference between these two balances is the depth of the bottom nylon shoe, or the measurement from heel to toe. See the illustration below. Compare both with your old hardware to see what matches best. For a stamp option choose 2920.

Comparison of the S380 and S385 balance shoes.

If you still need those Top Sash Guides as well, please send us front and side photos of an undamaged one, and we'd be happy to help with that as well.