A set of four Sorbo AAA batteries that are recharged from a USB power source instead of a separate battery charger. The pack comes with a storage box and the charging cables, so the batteries can be topped up from a laptop, power bank, car USB port or wall adapter. Rechargeable AAA cells are a sensible choice for devices that eat batteries, such as TV remotes, wireless mice and keyboards, headlamps, small torches, toys and game controllers, and the box keeps the set together in a drawer or travel bag. We could not find Sorbo's own specification sheet for this pack, so capacity, voltage and charging time are not listed here; check the packaging for those details before use.