Searching for 20 2 cx cmc 11 sash springs

Hello, Lance. It looks like you have two very different balances here. One is shorter, with winged nylon fittings, while the other is much longer, and its nylon fittings have no wings at all.

In the case of the shorter balance, you want either the Series 380 or Series 385, depending on the depth of the bottom fitting. That's the only difference between them. For the longer balance, you want either the Series 351 or Series 390. Same story here; the only difference is the depth of the shoe. These just don't have any wings.