Help with Sigma specs

I've just upgraded my old lens and want to sell it on Ebay but can't find ANY specifications about it other than what is on the lens. It is a Sigma Zoom 28-90mm 1:3.5-5.6 Macro. I use it on my Canon DSLR. What I need to know is what kind of mount it has. It fits my Canon, but does that make it a lens for Canon cameras or will it fit other cameras as well. Is it a lens designed for 35mm? How to tell? Any info would be greatly appreciated!

Why not try the SigmaUser website and see if anyone there can help? The fitting will be exclusive to Canon, but you'll need to know if it is a full 35mm frame lens or a digital-only one. There are designations to show this, but it's not my area of expertise.

John