Technical Specifications Driver size: 8mm Dynamic frequency response range: 20Hz20kHz Sensitivity: 99dB SPL@1kHz/1mW Max input power: 15mW Transmit sensitivity: -19dBV@1kHz/Pa Impedance: 16ohm Bluetooth transmitted power: 0-4dbm Bluetooth transmitted modulation: GFSK, π/4-DQPSK, 8DPSK Bluetooth frequency: 2.402GHz-2.48GHz Profile version: A2DP V1.3, AVRCP V1.6, HFP V1.7 Bluetooth version: V5.0 Battery type: Polymer Li-ion Battery (3.85V DC, 130mAh) Charging time: 2 hours Music play time with BT on: Up to 10 hours Weight (g): 19.8g IPX Rating: IPX5 What’s in the box: 1 x Endurance Run 2 wireless 3 x Sizes of ear tips 1 x Enhancer 1 x USC-C Charging Cable 1 x Warranty/Warning (W / !) 1 x QSG/Safety Sheet (S / i)