The Upgrade Item in Pokemon GO
The upgrade item in Pokemon GO is a special enhancement item that helps certain pocket monsters become more powerful. It's an essential way to master evolution and expanding the Pokedex.
The players can upgrade their items by spinning Photo Discs in PokeStops or Gyms for a whole week and by completing Field Research tasks that are specific to an event. These items are scarce however they are available.

Porygon2 can be evolved by using this item
In Pokemon Go, players can make use of a special item called the Upgrade to evolve certain Pokemon into more powerful forms. The process involves some steps that aren't difficult to do and provides some extra depth to the game's gameplay.
Porygon is one of the most distinctive Pokemon in the Pokemon series. It is able to evolve to Porygon2 or Porygon-Z. To unlock these evolutions, you'll need possess a few items. These include the Upgrade and Dubious disc. Although item upgrade are scarce however, they're not impossible find in the game.
The Upgrade is a rare item that is used to unlock the second level of evolution for Pokemon Porygon in Pokemon GO. To unlock this item, players have to capture and transfer Porygon. It's best to collect as many Porygons as possible. Each capture and transfer will result in one Candy. Trainers can also get this item by spinning PokeStops which are likely to dropping the item along with other rewards.
The Dubious Disc is another rare item in Pokemon GO that can be used to transform Porygon into a more powerful form. To acquire this item, players must collect 50 pieces of Porygon Candy. This can be accomplished by collecting Porygon and transferring them to Professor Willow, or walking with the Pokemon as their companion. Trainers can also get this rare item by spinning PokeStops though it's a bit more difficult to land on one.
It's a fun way give depth to your Pokemon GO experience. It requires a few unique items and in-game currency, but it's not overly hard to accomplish.
In contrast to other Pokemon in the series, Porygon can only be transformed into its second and final form using an item called the Upgrade. It is extremely rare and is only available by spinning PokeStops, or by doing research Breakthroughs. It is also possible to obtain the item by trading a Porygon when it has the item attached, or by using a Special Trade Item.
This is a special drop from the level 4.
An upgrade item is an item used to improve equipment by adding additional attribute bonuses. Upgrades are available in the game's Inventory from karma merchants, or as rewards for events. They can be added to weapons, armor trinkets, trinkets, or gathering tools. Upgrades can be placed in any slot on an item that is equipped. Some upgrades require that an item with higher quality be added. The majority of upgrade components can be replaced, but doing so will destroy the previous one. Only a few types of upgrade are salvageable by using salvage kits that are of high quality such as the Black Lion Salvage Kit and Ascended Salvage Tool.
Upgrades can be achieved by by combining an upgrade item with the item it's placed in or by rerolling the item with the rerolling token. The new item will have the same extra attributes as the original but will also be upgraded to a higher level and tier. Each item has an upgrade level maximum and minimum level. The rarity and level of the item determine the level. Each level is divided into three levels. Each level has its own upgrade cost and bonuses.
Generally, upgrading an item will increase its primary stat by a certain amount, and also provide a random extra stat. As an item's tier increases it will cost more to upgrade it will rise. However, there are discounts for specific items and with each upgrade, the number of upgrades needed will decrease.
The upgrade item is obtainable by spinning Photo Disks in PokeStops or Gyms. However, it has a very low probability of dropping each day. It can be earned by spinning at least one PokeStop Photo Disc or gym Photo Disc each day for a 7-day streak as well as by completing research tasks and other task-specific events.