The mics in the Sennheiser e815S Microphone 3-Pack will give you rugged, reliable service. Their cardioid pickup pattern rejects rear-axis sounds. Sennheiser e8155s feature metal construction, internal shockmounting, hum compensating coil, neodymium ferrous magnet with boron, and on/off switch with on-lock. 80Hz-12kHz. Precision manufactured in Germany. Includes a 10-year warranty!