Euros GS-1 (EURUS GS-1) is an electric guitar with a built-in synthesizer introduced by BOSS, a product that allows you to add synth sound to the way you play the guitar.
You can register up to 6 sounds in the body and switch between them. You can also change parameters while playing by simply pressing and turning the SYNTH CTL knob. Wireless communication supports Bluetooth and can be linked with a smartphone through this. Related information can be found here.