Masterball

The Masterball is a type of pokéball. It will always catch a wild Pokémon after defeating it if is the highest type of pokeball active and there is a remaining supply in the pokeball selector.

Description
The ultimate pokeball to capture Pokémon with, it has a 100% catch rate. Each time it is purchased it becomes 35% more expensive, increasing to the price cap at 100 times the base price.

Note: The Sinnoh Berry Master in Hearthome City also offers daily trades for Masterballs.