Fangrui Product Details Fangrui Product Details Smart Guitar Chord Trainer With Lighting Feedback: This Updated Chord Trainer Features 24 Transparent Keys Which Light Up In Different Colors To Guide Chord Practice. Red Key Needs To Be Pressed And If Pressed Correctly It Turn To Green Color. Three Practice Modes: The Pocket Guitar Is Built With 3 Practice Modes-manual (cho), Automatic (auto) And Exercise Mode (exe) Which Cater To Different Needs. The Difference For Cho And Auto Is To Switch Chords Manually Or Automatically While Exe Focuses On Finger Exercise On Fretboard Without Involving Chord Practice. Rotatable Screen For Better View: The Screen Of The Travel Guitar Can Be Rotated To Its Left To 30, 45 Or 90 Degrees For A Better View When Practicing. The Practice Is Silent And Does Not Make Any Sound. Rechargeable Compact: The Chord Trainer Is Built With Rechargeable Lithium Polymer Battery And Takes 4 Hours To Get A Full Charge And Lasts Approximately 8 Hours Of Use. A Type C Charging Cable Is Included. The Mini Chord Trainer Is Designed To Help