Sash Guide and Channel Balance

Thanks for posting. This looks like either a S351-29 or S390-29. The only difference between these two balances is the 'depth' of the bottom nylon shoe, so compare both with your old hardware to see what matches best. If your balance is stamped 2820, this would indeed correspond to our stamp option of 2820, which is for a window sash in the weight range of 12 through 16 lbs. Finally, yes, your Top Sash Guide does look like our 18-166. Just go over the dimensions to confirm.