Cables and batteries while recording are no longer necessary with the BY-V1. The transmitter with built-in microphone clips onto the clothing of the person you want to capture. The built-in battery provides up to 9 hours of power. The sound is recorded by your iPhone or iPad. Just plug the receiver into the Lightning port of your iOS device. The BY-V1 is immediately ready to use; both with audio and video apps. You simply start your video recording with the standard iOS/iPadOS app. This way, your recordings are automatically provided with sound from the microphone.