Channel Balance Option

I'm skeptical that you've narrowed it down to the S385-13. You see, for a "13 2" stamp, you're usually dealing with a 14" balance. Double check your measurement. The balance should measure 14" from one end of the metal channel to the other. Don't measure the plastic, just the metal. If the stamp is correct and you identified the Series 385 properly, you need an S385-14 with a 1320 stamp to match your "13 2". You want to double check the Series though. The Series 385 measures 1-3/32" from the front of the bottom shoe to the back. Measure your shoe as shown below. If it measures 1-3/32", go with a Series 385. For a 1" shoe, choose an S380-14.

"13 2" usually corresponds to a 1320 stamp option. You can verify this by weighing your sash and comparing it to the chart on the item webpage.