3.5mm Listen Only Acoustic Tube Earphone; Ear Tip MATERIAL: Soft and comfortable Silicon. Made of a durable, long lasting, hypoallergenic, medical grade polymer. Earplug can be rotated left and right ears and wear comfortably. The earpiece allows the user to hear in high noise environments. Works with standard, Incom, Yaesu, Alinco, Moto and Adi transceivers and also fits radio speaker mics, MP3 players and similar devices with 3.5mm connector. This model of the HYS TC-617-1N listen only earphone is designed for law enforcement officers, firemen, EMTs ,Sports, Fairground and other professionals who wear their radio with a microphone on their shoulder or clipped to their shirt.