Headphones; Microphones; Woofers; Audio cassette recorders; Audio interfaces; Audio speakers; Audio- and video-receivers; Earpads for headphones; Electrical pickups for use with musical instruments; Mileage recorders for vehicles; Music headphones; Remote video monitoring system consisting primarily of a camera and video monitor for recording and transmitting images to a remote location; Set-top boxes; Sound mixers; Sound and video recording and playback machines