USAMS TWS SM-Series comfort headset. Comfort and great design in one. Thanks to the use of tri-band tone equalisation, the sound from the headphones is clearer and noise-free. Small and lightweight, they will accompany you everywhere - at work, during exercise or while cycling. The headphones with built-in microphone use the Bluetooth 5.0 standard. This is the headset for those who need a lightweight, stylish design for listening to music and making high-quality calls. Enhanced touch control, 3D stereo surround sound, long battery life, stable transmission. The set furthermore includes a dedicated case that acts as a 320mAh power bank. Product features: - Bluetooth version: 5.0 - Sensitivity: 103 ± 3db - Communication range: up to 10 metres - Speaker diameter: 13 mm - Frequency response: 20 Hz ~ 20 KHz - Impedance: 32 ? ± 15% - Earphone weight: approximately 3g x2 - Headphones battery capacity: 30 mAh - Playback time: approx. 3h (at 60% volume) - Charging case weight: approx. 33g - Battery capacity of case: 320 mAh - Charging time of case: approx. 1.5 hours