Evolution Items are equipment which evolve pokemons that normally non-evolvable by levelling up, when they enter battles with these items.
Shiny Stone can be unlocked by searching northwest of Goldenrod City, after then it can be purchased at SnD Item Store.
Metal coat can be unlocked by searching northwest of Route 32, after then it can be purchased at SnD Item Store.
Pokemons evolving with Metal Coat need to be traded.
Pokemons evolving with King's Rock need to be traded.