These are the Calus N9pro wireless neckband earphones in black.Connectivity: Features Bluetooth V5.4 for a stable wireless connection.Battery: Offers up to 20 hours of continuous playback and approximately 90 days of standby time.Design: Lightweight, ergonomic neckband with magnetic earbuds to keep them together when not in use.Audio: Equipped with Hi-Fi stereo sound and "heavy bass" technology.