Screen corners.

Looks like you are showing us a screen frame section. We don't sell screen framing, but it's available at many hardware stores.

If you need corners that fit into this frame, we need to see the corners. We cannot identify them from the framing material. Why don't you update us so we can take a shot at identifying the part?

Take a look at the 95-054 and 95-129 corner keys. I believe these are the type that fit your screen frame. Take a look and compare our sizes to the ones you need.