30" channel balance

I am quite certain the other wing simply broke off the bottom nylon shoe, in which case the S377-30 seems promising. Just go over all the dimensions, particular of the top attachment (our 19-018), to ensure they match your old hardware. You'll need to pick a stamp option, which is usually determined by the stamp code on the metal channel. If there is none, or you are uncertain, obtain the exact weight of your window sash. You can then match that exact weight with one of the weight ranges listed alongside each stamp option on the product page.