CQtransceiver Rugged Throat Mic Headset with Glove Use PTT and Tube Earpiece for Midland Radio GXT300 GXT325 Two sensors design to make the quality of sound more true and clear extended 3.5mm earphone jack inlcuded Hear your HAM friends clearly even in noisy environment as your voice is transmitted via vibration of your throat Heavy duty PTT The elastic Velcro strap that suits head sizes from 12 to 25 inches. You can adjust the size freely.