Trantec
S4.04 Theatre Headset System (MIC-SJ22-P)

The S4.04 Series Theatre Headset System comes with a Beltpack Transmitter, a Headset Microphone (MIC-SJ22), and a UHF Wireless Tuner. It is available on channel 70 with 4 switchable licence free frequencies and fully synthesized PLL quartz tuning technology.
 

Specifications
Receiver
Diversity Reception	Antenna Diversity
Sensitivity	10uV at 45dBA, S/N
Squelch	Tone SQ, Carrier SQ, Noise SQ
Audio Frequency Response	50Hz – 15kHz
Audio Output Level (Max.)	Balanced (XLR socket): -20dBu, Unbalanced(1/4″ jack socket): 10dBu
Power Supply	12 VDC 500mA
Dimensions	215(W) x 39(H) x 102(D)mm
Weight	480g
Beltpack Transmitter
RF Carrier Power	10mW
Audio Frequency Response	50Hz – 15kHz
Audio Input Level	-6dBV (maximum), mic gain 0dB
Battery Life	Approximately 10 hours
Power Supply	1 AA size battery, 1.5V
Finish	Resin, coating
Dimensions	62(W) x 100(H) x 25(D)mm
Weight	85g with battery