Radio Earpiece for Motorola (2.5mm Single Pin with locking twist) Two-Way Radios SL300, SL2600, SL3500e, SL7550, SL7580e, SL1K Business Radios. Replacement PMLN7157A,PMLN7189A PMLN7189 Headset. Acoustic Tube- The acoustic tube earpiece is one of the most popular and versatile earpieces. Low-profile, flexible, transparent acoustic tube transmit sound in high quality the transparent tube would be hardly noticed by others around you. Earpiece Mic- Built-in electric mic. The hidden micro-speaker is located in the centre of PTT switch. The push to talk (PTT) mic is sensitive and directional, so you don't have to turn or tilt your head to transmit. Microphone and push-to-talk are conveniently located inline on the wire, making communication simple and unobtrusive. PU Cable- Good quality cables tend to be soft, flexible and resistant to snagging. The polyurethane-jacketed, Kevlar coated cabling provides extended field life. One Wire Earpiece is the most popular, most bas