iTestMic2 is the only direct-connect iOS calibrated test & measurement microphone that includes a 3.5mm analog audio output and iOS device charging. Plug it into your iOS device for instant, accurate SPL readings, plug in a 3.5mm (1/8") audio cable to get audio output signals, and plug in the included power adapter for long-term noise studies or just to charge your iOS device. iTestMic2 is the perfect companion for iPhone 7, since it has an audio output and also allows simultaneous device charging.