[ Audio- and video-receivers; Baby monitors; Cabinets for loudspeakers; Cassette players; ] Headphones; [ Portable media players; Protective cases for smartphones; Radio sets; Rechargeable electric batteries; Wireless controllers to remotely monitor and control the function and status of other electrical, electronic, and mechanical devices or systems, namely remote metering systems, gas and liquid cylinders, vehicle tracking devices, energy and utility systems, security systems, lighting syst...