These Emax 2204 motors are designed for a ~300 size or similar multicopter frame. With a massive 2300kv spin speed, these produce a huge amount of thrust for a fun and zippy multicopter.
Thrust: 440g (3s, 6*3 prop), 675g (4s, 6*45 prop)
Cells: 2-3 (4 cells tested confirmed to be okay)
Mount holes: 19/16mm