28c balance stamped

Hello! It looks like you need the Series 795 tilt channel balance. The bottom T-shaped shoe that comes with this balance is 1-1/4" wide, but yours appears to be around 1". If so, you'll need to purchase the 15-194 separately and then swap the shoes out. Take a look at the video below, it'll show you exactly how to do this.

The Series 795 installs at the top using a screw. We can't see how yours installs since the clip appears to have broken off. If it's anything other than a screw we'll have to see it as it may need to be custom made. 

It sounds like your balance uses a hook instead of a screw tab. The Series 795 comes with a screw tab by default so there's a chance you might need a custom version with a hook. 

Could you show us a picture of the hole itself to confirm? 

Thanks for this photo. That's a huge help. Based on this photo, you will need a custom order balance. Most windows have a square hole that allow you to just throw a screw plug in there to use our standard balance, but your hole is round which means that solution won't work in this case. 

I recommend returning the balances you bought for a refund before you do anything else. You can see our return policy here.

Then you can place an order for the custom balances using the link I'm about to email you now. This will be the same thing you bought before, except they'll come with the 15-194 shoe and 15-198 hook on top.