Amazon.com : SOONSUN Frame Mount Housing Case with External Lavalier Lapel Clip-on Microphone for GoPro Hero 3, Hero3+, Hero 4 Black White Silver Action Cameras : Electronics
Polsen GPMK-22 GoPro Production Microphone Kit GPMK-22 B&H Photo
Amazon.com: Hero 4 Microphone Compatible with GoPro Hero 4 Silver Black White Edition, Hero 3, Canon, Nikon Camcorder DSLR Camera - External Lavalier Lapel Mic : Electronics