I'm looking for the specific piece

Thanks for reaching out! Your coil support appears to be the 15-205 which is the coil triple support typically used for the Series 165 Coil Spring, which has a 3/8" thickness. To determine the spring strength, you'll need to look for a stamp/marking on the metal coil.

The pivot shoe typically compatible with this cover and coil spring is the 15-199. To determine if this is the right replacement shoe, you'll want to compare the dimensions. If your shoe is different, I'll need to see a photo of your existing pivot shoe removed from the window.

Alternate view of 15-199

Let me know if you have any questions.