Genuine original Canon part, brand new. Canon original parts # YF2-2023. It DON'T have serial # on the mount.

It's compatible with 7 Canon lens models:

EF 24-70mm 2.8 L USM II lens

EF35mm F1.4L II USM lens

EF 70-300 mm 1:4-5.6L IS USM lens

EF16-35mm F4L IS USM

EF16-35mm F2.8L III USM

EF11-24mm F4L USM

EF 28-300 mm 1:3.5-5.6 L IS USM

If you lens is not belong to these models, it won't fit.

*** Custom Declaration: If you have the concern, please message before or right after the purchase.