Mi-Si Magpie Air Active Magnetic Soundhole Pickup & MicThe Mi-Si Magpie Air includes the revolutionary new active, battery-free magnetic soundhole pickup for acoustic guitar and the Mi-Si Power Charger.The Magpie Air pickup employs a unique “planar” single coil design - less susceptible to AC hum than traditional bobbin wound pickups. This design provides much broader sound and reduces the overall weight - combining the benefits of a single coil pickup with the virtually hum-free operation of a humbucker. The sound of Magpie Air is augmented with signal from internally mounted MEMS microphone.Powering up the Magpie Air for 60 seconds with the Mi-Si Power Charger will provide you with up to 6 hours of performance time.Features:--Battery-free active magnetic soundhole pickup for acoustic guitar-Hum-Free Planar Single Coil Design-Two separate volume controls for pickup and microphone-Rechargeable preamp (No batteries needed)-A 60 sec. charge allows for up to 6 hours of performance.