For two-way radios, CD Player, MP3 players and similar devices with 3.5mm jack plug TC-617 Radio Earpiece clear sound performance. TC-617 Radio Earpiece adjusts to fit either the left or right ear Excellent for use in police, military, nightclubs, bars, paintball, security, restaurants, hotels, bouncer, warehouses, and noisy environments. works with standard, Incom, Yaesu, Alinco, Motorola and Adi transceivers and also fits radio speaker mics, MP3 players and similar devices with 3.5mm connector