MD 504 is a Sennheiser professional microphone in the microphones category. The device employs a dynamic transducer with a cardioid pickup pattern suitable for live vocal applications and general purpose amplification. It provides a balanced XLR-3 output with standard microphone impedance and is housed in a rugged metal enclosure for durability. The design emphasizes low handling noise, consistent polar response, and compatibility with standard preamps and mixing consoles.