This is the amazingly tiny F3 Femto flight controller from Emax. This is designed for micro quads of the size 150mm and under measuring at just 20mmx20mm and weighing just 2.2g. Don't be fooled by the size though, the F3 Femto is packed full of features. For instance, this tiny FC is not just an FC...it's also a PDB! It also has an integrated buzzer, BEC and vbat (battery monitoring) - what more could you ask for?
Read on for the manual