An ability or item that increases the effects or duration of items used. The Item Caddy often has this ability.
Examples include The Medic being able to heal more when using healing items, or able to heal more than one target with a single item.
Compare Amplifier Artifact, an item that boosts the user's already existing powers, Quad Damage, a power-up to a character's stats, and Money Multiplier, [...] [tvtropes.org]