Hot Ptt Shoulder Microphone Speaker Mic For Baofeng Uv-5r Bf-888s Bf-uv82 Bf-uv9r Waterproof Walkie Talkie Two Way Radio - Buy Speaker For Tour Guide,Bluetooth Speaker Microphone,Baofeng Product on Alibaba.com
Collin's Lab: DIY Contact Mic - Make:
Make a Contact Microphone : 10 Steps (with Pictures) - Instructables