Yaesu MH-73A4B – Submersible Speaker / Microphone

Submersible IPX7 (1 meter for 30 minutes)
Mic Element: Electret Condenser
Mic Impendance – 680 Ohm or less
Speaker Impedance – 4 Ohm
Output Sound Pressure Level – 81.5 dB   2dB/W (1 m)
 Rated Input – 0.5W
Maximum Input – 1.0W
Dimensions (W x H x D) – 2.4″ x 3.3″ x 1.5″
60 x 85 x 37.5 mm
Weight – 5.3 oz (150 g)