Window Balance 20 4 DS Caldwell

I am willing to bet that your balance only measures 22" if you include the plastic. Measure the metal by itself, and I suspect you'll come up with 21". Double-check. If so, this is S385-21 or S380-21. You'll want to consider the 2040 stamp option for windows between 15 and 23 pounds, and measure your bottom shoe like the photo below to determine which Series. Series 380 has the 1" shoe, and Series 385 has the 1-3/32" shoe.