This page contains information regarding Star Trek: Lower Decks, and thus may contain spoilers.
An anti-grav sled, also known as an anti-grav unit and sometimes referred to simply as an anti-grav, was a device used to carry objects which were too heavy to lift manually. The technology used was similar to a hovercraft or an anti-grav lift. It contained graviton inverter circuits, transfer coils, and a flow capacitor. The sled produced antigraviton fields.
Kasidy Yates and her crew sometimes used anti-grav sleds to transport cargo into her cargo ship. Although Benjamin Sisko suggested using the transporter instead, her transporter was a Mk. V, which was ill-equipped to transport unstable biomatter. (DS9: "Family Business")