Audio interfaces; Audio equaliser apparatus; Cabinets for loudspeakers; Cases for smartphones; Chargers for electric batteries; Earphones and headphones; Headphones; Horns for loudspeakers; Loudspeakers; Megaphones; Microphones; Rechargeable electric batteries; Sound transmitting apparatus; Subwoofers; USB cables; Virtual reality headsets; Wireless chargers; Wireless speakers; Acoustic membranes; Data processing equipment, namely, couplers