Dirty Lens

I’ve just noticed something that looks like dirt inside front glass on my 55-300 lens. I’ve just replaced it with the WR version. Was getting it ready for sale when I noticed it.
Any ideas ?

Hi
From what I can gather from second hand lenses offered for sale by dealers, dust is by no means unusual and shouldn't detract from the image as the lens cannot actually focus on it. Hopefully, this will help

Michael

I can only see dust in that image and I can't tell how much is internal and how much is external. Some internal dust is impossible to avoid and won't detract from the image unless there's a lot, where it will lower contrast a little.