In the core series games
If held by a Slowbro (or is present in the player's Bag)PE, allows it to Mega Evolve into Mega Slowbro if its Trainer has a Key Stone. Each Trainer can only Mega Evolve one Pokémon per battle.
Unaffected by item negating effects (such as Embargo and Klutz). Item manipulating effects (such as Trick and Fling) cannot give Slowbro a Slowbronite or remove a Slowbronite from Slowbro.
Outside of battle
If held by a Slowbro, allows it to Mega Evolve into Mega Slowbro when it performs a Spectacular Talent during a Pokémon Contest Spectacular while its Trainer has a Key Stone. Slowbro will remain a Mega Slowbro until the Talent Round ends.
Pokémon holding Slowbronite in Pokémon Omega Ruby and Alpha Sapphire cannot be traded to Pokémon X and Y.
| One of a variety of mysterious Mega Stones. Have Slowbro hold it, and this stone will enable it to Mega Evolve during battle.
|| One of a variety of mysterious Mega Stones. This stone will enable Slowbro to Mega Evolve during battle.
In spin-off games
|| This section is incomplete.|
Please feel free to edit this section to add missing information and complete it.
In Pokémon Shuffle, the Slowbronite allows the player to Mega Evolve Slowbro.
The player can obtain the Slowbronite by defeating Mega Slowbro in Stage 45 found on Isla Azul.
The Slowbronite enables the following Mega Evolution:
|| Mega Slowbro
|| Adds one more Mega Slowbro above the match.
Actually converts the tiles directly above all other Mega Slowbro into a Mega Slowbro. This effect can replace any disruption in the tile above and counts as erasing the content of the tile for damage, but does not affect black-cloud disruptions. Does nothing if the above tile is empty.
In the manga
In the Pokémon Adventures manga
In Omega Alpha Adventure 7, Jinga was revealed to possess a Slowbronite, which he used to Mega Evolve his Slowbro.
In other languages
|| 呆殼獸進化石 Ngòihhoksau Jeunfa Sehk
|| 呆殼獸進化石 / 呆壳兽进化石 Dāikéshòu Jìnhuà Shí
|| 야도란나이트 Yadonrannite