Balance is 29" (metal only), Markings are: 28C USB

The shoe on your balance looks like it may have a 7/8" depth like the one on the S378-29 Channel Balance. To confirm that this is the correct replacement, be sure to double check the depth of the shoe.

For this 28C stamp, you may be able to use the 2830 stamp option but you may also want to check that your sash weight falls between 16 to 23lbs.

Close up view of the S378 balance shoe