Offering outstanding Audio-Technica sound for surface-mount applications, the U851A features a PivotPoint® rotating output connector, UniSteep® filter and UniGuard® RFI-shielding technology. This battery- or phantom-powered condenser microphone accepts interchangeable condenser elements-available for boundary microphones in cardioid, hypercardioid and omnidirectional polar patterns. Its heavy die-cast case and silicon foam bottom pads minimize coupling of surface vibration to the microphone. With superior off-axis rejection and maximum gain-before-feedback, this professional microphone sets audio-quality standards in challenging acoustic environments.