HQRP® Hands Free with Earpiece! When you need to be discreet and leave your hands free to complete whatever important tasks land at your feet, you can't beat this neat little earpiece specially designed to meet your needs. Whether you're in security, retail, hospitality, or any other job that requires radio communication as well as a free hand or two, you can clip this earpiece onto your shirt and begin using your radio device to communicate discretely and easily. Excellent for use in police, military, nightclubs, bars, paintball, security, restaurants, hotels, bouncer, warehouses, and noisy environments.Resistance: 90Ohm±15%;Sound Pressure Level: 115dB S.P.L;Rated Power: 500mW;Max Power: 800mW;Microphone Sensitivity: -34 ± 2dB RL=2.2KOhm Vs=3.0V(DC) 1KHz 0dB=1V/Pa;Microphone Resistance: 2.2KOhm 1kHz (RL=2.2KOhm).