Specification: Model: K20 Type of microphone: built-in Operating voltage: 3.7V Bluetooth version: 5.2 Charging time: 1.5 hours Charging voltage: DC5V Number of headphones: only one Form factor: ear hook Connectivity: Bluetooth Wireless technology: Bluetooth Bluetooth distance: 33ft/10m Colour: Black Built-in battery: 180 mAh Type: Earbuds (In-Ear) Noise cancellation: CVC6.0 Features: connects two devices, comes with earbuds, high capacity battery, IP7 waterproof Package Included: 1x Earphone 1x Charging Cable 1x User Manual 2x Replacement Ear Caps