Tuner monster
Tuner Monsters are required for the Synchro Summon of a Synchro Monster. When the total Level of the Tuner monster and the other monsters on your side of the field matches the Synchro monster's Level, by sending them to the Graveyard, you can Summon the Synchro Monster.
Tuner Monsters are the first secondary Type of Normal Monsters, and the fifth secondary Type of Effect Monsters, like Union and Spirit Monsters. Subsequently, Tuner Monsters can be either Effect Monsters or Normal Monsters.
Most Tuner Monsters are low in Level, usually ranging from Level 1 to Level 4, but they have effects that allow them to facilitate the summoning of a Synchro Monster, often by Summoning other monsters, or altering their own Level.
There are a few support cards that specifically deal with Tuner Monsters, including "Revival Gift" and "Quillbolt Hedgehog", which further aid in setting up a Synchro Summon.
