1. Light to 133 grams, easy to wear, lecture not tired2. Using 13-core Rutilon speaker, with excellent sound quality, loud volume does not break the sound and not harsh3. Using digital efficacy system, low distortion, high clarity4. Noise reduction microphone / noise reduction speaker, no whistling, so that the sound is more dynamic5. Support insert TF card / U disk, can be used while chargingParameters:1. Material: ABS2. Rated power: 5W3. Input voltage: DC 3.7V DC 5.0V4. Li-ion battery capacity: 1500 mA5. Frequency response range: 40Hz-20KHz6. Distortion: +/- 1% (3.7V, 1Khz, 1W)7. Signal to noise ratio: 83dB8. Playback format: MP39. Impedance: 2Ω10. Operating temperature: -5 ~ 40 degrees Celsius11. Size: 85 x 85 x 34mmPackage includes:1 x mini audio speaker1 x Wired Headset Microphone1 x Belt1 x usb data cable1 x instruction manualSpecification: Package Weight One Package Weight 0.30kgs / 0.65lb One Package Size 18cm * 14cm * 8cm / 7.09inch * 5.51inch * 3.15inch Qty per Carton 98 Carton Weight 30.00kgs / 66.14lb Carton Size 50cm * 50cm * 60cm / 19.69inch * 19.69inch * 23.62inch Loading Container 20GP: 177 cartons * 98 pcs = 17346 pcs 40HQ: 412 cartons * 98 pcs = 40376 pcs