nope thats a standard towball ,right size ball but not a alko neck see photo below for the two distinct types one on left is a greased normal tow ball one on right is a alko dry towball
you can see the height difference easily in this ,get on to the fitters asap and insist they change it for the proper type .the longer neck is made for a reason ,DO NOT LET THEM FOB YOU OFF it could invalidate your insurance in case of a accident
It's a steel plate that protects your car they come in either black or stainless steel ,when I had my tow bar fitted the other week it cost me £9 for. A Stainless one .just do a google for them
I will ask husband to see if they can do that too. They admitted it is wrong and are coming to change it next week
Edited to add: doesnt change the fact I asked the guy right out "is this going to suitable for our alko hitch" and he said "the one with the red handle you pull down *glances at my hitch* yeah its the right one for that"
Shouldn't take them more than 5 minutes to change. I was a little surprised though I have never seen a standard ball painted black before. A standard ball is about a fiver, an AlKo compatible ball about a tenner, and about £30 for a genuine AlKo one.