Mystery Part

Hi all,
So yesterday when I got home I found this part under my car in the garage.Does anyone know if this may be a car Part,mower Part or something else ? It says 9.8 on it. Thanks so much, I appreciate it.

Attached Images

• IMG_0375.jpg (78.6 KB)
• IMG_0376.jpg (82.8 KB)
• IMG_0377.jpg (69.6 KB)

Mystery Part