This JOYO JMT-550 metro-tuner is incredibly accurate with built-in amplifier and drumbeats which will surely change the way you play and listen to music. This tuner is not like a regular metronome and has additional functions for Rhythm Play as well as amplifier monitor and also MP3 input. Specifications: Function: JOYO JMT-550 Metro Tuner with Built-in Amplifier and Drumbeats Feature: - A digital metro-tuner with built-in amplifier and drumbeats. - Compact size and multi-functional， the tone is more accurate. - With a INPUT jack that use audio cable to connect guitar or other equipment. - With a AUXIN jack to connect MP3 and other audio device. - Automatically save the last settings including under Tuner / Metronome / Rhythm Play mode: Tempo， Rhythm and Rhythm Pattern. - With a stand in the back， can be pulled out to keep it up right when in use. Brand: JOYO Model: JMT-550 Modes: Tuner / Metronome / Rhythm Play Tuner: - A4 Frequency: 410 ~ 450Hz - Tuning Range: 0A(27.5Hz) - 8C(4186.01Hz) - Flat: None / b / bb - Model Sound: 4C - 4B - Tolerance: + / - 1cent Metronome: - Tempo: 40 ~ 208 bpm - Beat: 0， 1， 2， 3， 4， 5， 6， 7， 8， 9 Rhythm Play: - Tempo: 40 ~ 208 bpm - 40 Types of Rhythm Pattern: Rock 1 / Rock 2 / Rock 3 / Rock 4 / Meta 11 / Meta 12 / Meta 13 / Meta 14 / POP 1 / POP 2 / Ballad 1 / Ballad 2 / Dance 1 / Dance 2 / Dance 3 / Blues / Fusion / Country / Rockabily / Disco / Rock Billy / Rock Boogie / Rock Cha Cha / Club Pop / Beat Soul / 60\'s Soul / Funk / 16 Beat Shuffle / Funk Shuffle / Fusion Shuffle / Blue Grass 1 / Blue Grass 2 / Blue Grass 3 / Pop Waltz / Hully Gully / Limbo Rock / Cha Cha / Viennese Waltz / Guad Dance / Slow Rock LED Indicator: - Under Tuner Mode: In Tune - Middle green light / Flat - Left red light / Sharp - Right red light - Under Metronome Mode: Strong Beats - Right red light / Weak Beats - Middle green light / Rhythm - Left red light - Under Rhythm Play Mode: The left and right lights both on means the thythm starts; alternative lighting means beating Input: INPUT， MIC， AUXIN Output: Built-in Speaker， earphone Power Source: DC 9V or 1 x 6F22 9V Battery (Not include) Color: White Product Weight: 108g Package Weight: 131g Product Dimensions (L x W x H): 116 x 73 x 25mm Package Dimensions (L x W x H): 136 x 77 x 30mm Approved: CE / FCC After Sales Service: 1 Year Warranty