Sennheiser XSW 2-ME2 B-band

Wireless Microphone System
Frequency range B: 614-638 MHz
8 frequency banks, each with up to 12 factory-preset channels
AF frequency response 50 to 16,000 Hz (–3 dB)
Microphone dynamic
AF frequency response 80-14,000 Hz
Power supply 2 AA size batteries, 1.5 V
Weight approx. 680g