The USB Dual Pre Kit from ART is a combination portable preamplifier and computer interface housed in a compact, rugged case. The unit is suitable for a wide variety of applications, including remote field work to desktop/studio recording. The 2 input channels can accept either a microphone or line input and provide up to 48 dB of gain. Phantom power is available for use with condenser microphones, even when running from the USB bus or any of the other powering options. Those include using an external power supply or an internal 9V battery (both available separately). When running off the battery, operational hours are in excess of 50 hours with phantom power off. A stereo mini headphone jack is provided for monitoring and the rear level and monitor mix controls allow for latency-free recording. The monitor mix is also routed to the main outputs. The USB interface is fully compliant with the USB 1.1 specification and uses USB adaptive mode for playback and USB asynchronous mode for record. It comes with 9V High Energy Alkaline Battery from Varta. It has a 5-year shelf life. Plus a 20-Inch XLR-XLR cable. Box Contains ART USB Dual Pre USB 1.1 Digital Audio Interface with Dual Microphone Preamps 1x Varta 9V High Energy Alkaline Battery 1x 20" XLR-XLR Cable 1x USB Cable