No adapter should be required. The Canon Rebel series cameras are part of the EOS line and use the same lens mount. The only issue you may encounter is that lenses intended for APS-C sensor cameras (Rebel, 10D, 20D, 20D, 40D, 60D, 7D, etc.) will not work properly on full frame cameras (such as the 5D MkII/MkIII, 6D, etc.).
The adapter in this listing is for mounting EOS lenses to the new Canon M mirrorless camera.
I have a canon EOS Rebel XT camera lenses and I am trying to mount the lenses onto an EOS 5D Mark II camera but they don't fit. Would you have something I can adapt them with to fit in? and if not what can I do for them to work?