6 item types can be equipped on the horse?

I have searched and searched for what u actually are able to equip into the left middle slot of the horse inventory. I can’t seem to find anything.

Was able to find some sweet armour for the head of my horse though in the nest. A lot easier to get that from the bottom climbing up rather than taking damage jumping off cliffs lol.

So the list is:

Saddle
Caparison
Chanfeon & criniere
Bridle
Shoes
And the sixth?

But ya anyone know what equips in this slot and can share a link. I’m sure it’s an oversight on my part but would appreciate the help pulling my head out of my ass. Cheers.