The Tascam iM2 turns the iPhone, iPad or iPod touch into a high-quality stereo recorder. The microphone level is adjustable with a knob on the side, making it quick to adjust without even looking at the unit. It"s powered through the dock connector so no battery is required. The iM2 has a stereo limiter preventing from sudden loud sounds,Features:*Stereo condenser microphones for iPhone 4, iPod touch or iPad dock connection *Microphones adjustable 180 degrees front to back *Built-in analog to digital converter and microphone preamp for low noise recording *125dB SPL maximum level for recording loud shows without distortion *Switchable limiter attenuates high-level signals to prevent recording overload *Adjustable input level control *Powered through iPhone, iPad or iPod touch dock connector *USB input allows the iPhone or iPad to be charged from a USB connection or optional TASCAM PS-P515U *Compact size ideal for mobile use *Compatible with iPhone 4, iPhone 4S, iPod touch 4G, iPad, iPad 2 *Dimensions: 2.3" W x 2.2" H x 0.75" D *Weight: 1.05 oz