Jamstik 7GT Guitar Trainer or performance guitar midsize I20 x 3.15 x 2 inches weight 1.6 pounds. It can be used as silent guitar and performing guitar. With 3.5mm stereo earphone jack and a 4O3W high-fidelity loudspeaker, you can enter the silent mode after plugging the earphone in it. You can switch the guitar tone of acoustic guitar and other electric guitar randomly.Smart guitar free of tone tuning, It is a powerful smart guitar of small size and big intelligence. nearly 100 groups of sensors and up to 7 CPUs to work in coordination. $200 value on amazon Smart Midi Guitar, black (SG7) never used