The CD in the lens box

[Good24]

Why do I always get a CD in the box containing a lens from Canon? It's black and it says "EF lens" on it, and also "Ver. 4.1."

I've never opened one. And yet my lenses still work? ;D

I'd be curious to know what it is, and what if any value it adds. I register my gear at Canon's website so if there are needed "downloads" (even then I don't really understand what those are for) I assume I can do it that way.

Any insight is appreciated. (Yes, obviously I am aware I could open it up finally and check it out ... but I think out of some vague sense of preserving potential resale value, coupled with my not understanding the benefit, makes me think it's better to leave it in its packaging.)

 

[Loswr]

It's the pdf lens manuals for most lenses. The newest lenses (e.g., 11-24/4L) come with a booklet.

 

[Good24]

Ah, very good, thank you. Yes these are older lenses (50L and 135L, e.g.).