This is an AF-S Nikkor 16-35mm f/4 lens, a member of the "small trinity" of lenses. I haven't used it much since I bought it new. Everything works perfectly. I'm selling it because I rarely use wide-angle lenses, maybe once a year. A lens protector is included as a bonus. (The photo shows an ND8 filter, but it's a regular protector.) The rear cap is a third-party product. There is no noticeable dust, mold, or fogging inside the lens. It's been stored in a dry cabinet and used infrequently, so it's in good condition.