Hello,
I am looking to replace 2 sets of channel balances for two different windows. I've attached pictures of the end pieces and stamps. The balances are both 1/2" wide and 29" long, without the end pieces. The markings on set one are 2840K and the second set is 2820D (backward D) and both of them have a little B.S.I. stamp underneath. The end pieces are identical in length, width and height for both sets. Please let me know if you have any additional questions. Thank you very much.
Luke