Energy Sistem Sport 1 Bluetooth Earphones (Blue) Colour:Blue   Created for workouts. Designed to enjoy. Bluetooth earphones for sport lovers, great sound and functionality. You can answer your calls and control music playing while working out. All this with a Secure-fit system.  Features: CONNECTIVITY Bluetooth v4.1, Class II Range: Up to 10 m.  DRIVERS Frequency response: 20 Hz ~ 20 KHz Diameter: 6 mm SPL: 103±3dB THD < 1% MICROPHONE Sensitivity: -42 dB±3 dB (@1 Khz)