[ Headphones; Portable media players; Earphone; Horns for loudspeakers; Audio- and video-receivers; protective films adapted for mobile phones; Telephone sheath; ] cases for smartphones [ ; covers for smartphones; wearable activity trackers; Couplers; electronic collars to train animals; Electrified fences; Dog whistles; portable remote retarder in the nature of a remote braking device for cars for use inside the vehicle ]