Causes Porygon to evolve into Porygon2 when traded while holding it, which consumes the Upgrade. Porygon will not evolve if linking to a Generation I game. In Pokémon Legends: Arceus, due to the absence of held items, the Upgrade simply needs to be used on Porygon to trigger the Evolution, which consumes the item.
While normally rare, from March 21, 2017 onward, the player is guaranteed to find an Evolution item when obtaining the bonus for spinning a Photo Disc for the seventh day in a row.
Additionally, the player receives an Upgrade when completing part 5 of the Special Research "A Ripple in Time".
In Pokémon Diamond and Pearl, when pluralized or prefixed with the indefinite article, this item's name is rendered with a lowercase 'g' ("Up-grades" and "an Up-grade", respectively). In Pokémon Platinum and Pokémon HeartGold and SoulSilver, both of these instances are corrected to display with a capital 'G' ("Up-Grades" and "an Up-Grade", respectively), matching how the item's name would normally be rendered.
