Fun cheap purchase 2021. Thank goodness they included the inside diameter measurement. A little over 2 inches matches the brake reservoir cap. Sold! After pulling the black cap it was confirmed the previous owner had it on a washer fluid cap. The washer fluid cap was almost dead on the size on my brake reservoir cap. part number 95.10.53P
Fitment cap vs cap
rubber oring makes it fit like a glove
Polished vs Brush? Polish matches my current strut bar, but brush matches my second engine build ideas.