I have a hidden tow hitch that has a slight wobble in it when the receiver is installed. This hitch pin is designed to pull the hitch to one side, tightening both horizontal and vertical movement. They also have a locking mechanism on them so your hitch can't be stolen (if yours is removeable like mine).
Repco currently have a 30% off sale making this $28 (previously $40). Hopefully this isn't store-specific; I've checked a number around my area and the price is consistent.
EDIT - Pricing appears to be region-specific. I've updated the title to reflect this.
If you want some info on what this product is used for, this YouTube video should help: https://www.youtube.com/watch?v=Ko4wV-dn7K8
Cheers,
Theo
Nice one! Picked this same hitch up from here for $32 in the last sale.