From the website:

• Self-contained guitar processing/modeling system which recreates a wide variety of guitar, pickup, amp, speaker cabinet and microphone sounds using a standard electric guitar equipped with GK-2A or compatible pickup (not included)
• GK-Ready 13-pin input plus 1/4" guitar input for direct access to amp/speaker modeling sections
• Hollow-body and acoustic guitar models including new nylon string guitar
• Extremely natural tube amp models and overdriven sounds
• HRM (Harmonic Restructure Modeling) creates synth-type sounds—including new brass sounds—with natural playing nuances and without delay
• Combination guitar output/GK pickup output for completely new types of sounds
• Polyphonic Intelligent Pitch Shifter for instant open tunings, 12-string guitars, bass guitar, string-assignable octave, slow gear, and more
• Effects include reverb, chorus, hexa-pan, delay, flanger and parametric EQ
• Extremely intuitive operation w/ helpful operational graphics and icons
• Onboard expression pedal for realtime parameter control
• Output Select switch for connection to conventional guitar amps or power amps
• Offers 200 Preset and 100 User Patches