Classified Adverts Image Size?

When advertising in the Classified Adverts For Sale section, is there a preferred size for any images attached to the post? Thank you.

Do you mean the section in the forum or the section in the menus at the top of the screen?

In the forum I tend to use 1000px wide which seems about right and loads quickly.

In the gallery and no doubt in the section for ads any size will do, just not smaller than that 1000px.

Hello John, thanks for the reply.
I mean in the Classified Adverts section. I may be advertising a lens for sale and wish to attach an image of it.