4.5mm F2.8 EX DC HSM Circular Fisheye

Hi everybody,
I would like to buy this lens:
4.5mm F2.8 EX DC HSM Circular Fisheye
http://www.sigmaphoto.com/shop/45mm-f28-ex-dc-hsm-circular-fisheye-sigma

I have Canon 550D. I can use it for my camera, is it right?
I mean I know I can mount it, but will every function work properly.
in the lens description we can read this:

"For use with smaller chip APS-c cameras only"....that means it is ok for Canon 550D, is it right?

I am sorry if the question is so trivial but I am just not sure this lens would be work with my camera

I need a full circular fish eye lens.

thx for helping
Imre