On the face of it, I can't tell at the moment, there's no number on the part itself and the pictures of the two are very similar.
But I assume that it is the AT502, as the Kenwood pages say that the AT502 is for the "XL & Major" models - and the AT501 says that it is for mixer size "Chef" (not "Chef XL"). (not "Chef XL") - the 502 lacks any size reference -- only in the English description the two parts are called "Creaming Beater Chef Size" and "Creaming Beater Chef XL Size". The German description by Kenwood is probably a little suboptimal here...

AT501: https://www.kenwoodworld.com/en-gb...
AT502: https://www.kenwoodworld.com/en-gb...