This is mine:
http://www.milenco.com/products/security/hitchlocks/super-heavy-duty-3004-hitchlock
Fits with no issues to my AKS3004 hitched or unhitched. Cannot use while towing as the Stabiler needs to be dis-engaged to fit.
As per the website: "Fits hitched or unhitched (not to be used on the hitch, whilst towing) fits AL-KO, AKS 2004, 3004, AKS10 Hitches".