Horseshoes of Speed

Source: D&D 5.2 SRD Magic Items

Wondrous Item, Rare

These horseshoes come in a set of four. As a Magic action, you can touch one of the horseshoes to the hoof of a horse or similar creature, whereupon the horseshoe affixes itself to the hoof. Removing a horseshoe also takes a Magic action.

While all four horseshoes are attached to the same creature, its Speed is increased by 30 feet.