A pair of magnetic gravity boots
Magnetic gravity boots were footwear worn by Starfleet officers, and presumably other spacefaring civilizations.
These boots providd stability by adhering to a compatible surface, useful when sufficient gravity (or artificial gravity) was not available, including extra-vehicular environments ("space walk" situations).
In 2293, Yeomans Burke and Samno wore magnetic gravity boots to assassinate Chancellor Gorkon, while artificial gravity was knocked out on the IKS Kronos One. Lieutenant Valeris later stowed one boot in Crewman Dax's locker to implicate him in the assassination. (Star Trek VI: The Undiscovered Country)