12 Optional Tones & 3 Fingerstyles - the M2 offers a diverse selection of 12 different tones. Adjustable fingering keys for selecting different fingerstyles: F Flute Fingering, Electric Piano Fingering, or Hulusi Fingering. 5 Blow Sensitivities (b (lightest), b2 (light), standard, heavy, and heaviest) & Adjustable Sound Effects. Bluetooth & Bluetooth MIDI Connection - Bluetooth can be used to connect to apps on your phone or iPad, such as Ziyueban, Tanchangba, and Perfect Piano.