Ultra Ball

A Great Ball high-performance Poké Ball that increases your chance of capturing a Pokémon by 200%.

Details
Ultra Balls are unlocked once the player hits Level 20. Upon leveling to 20, the player receives 20 free Ultra Balls and they become available via PokéStops.

In-game description
An ultra-high performance Poké Ball that provides a higher Pokémon catch rate than a Great Ball.

Trivia

 * Becomes available from PokéStops at Level 20.