DIY Supplies:ELECTRICAL Certification:CE Introduction to bone conduction technology Bone conduction is a magical sound transmission method. The sound is transmitted entirely through bones. The bone conduction module uses the skull and jaw as the sound transmission medium, bypassing the tympanic membrane and auditory ossicles, and directly transmits the sound to the auditory nerve. The magical thing about it is that the sound seems to come from the ear, but it feels a little ethereal, as if deep into the bones. GD01: Dimensions: 21.5*14*7.9mm Power Nominal input 1.5W, Maximum input 3W Average voltage :3.7 V Operate (Max) :12 V Nominal Impedance :4.515% test @200Hz 3 v Resonance frequency :300-19000HZ Sound pressure level (minutes) :In the case of 88-1kHz decibels Current consumption (maximum): 600MA Distortion :5% less Operating temperature :-20---60 C Storage temperature: -30---+70 C Dual channel Bluetooth Board Package Include 1Battary not Include 2No hot melt glue, convenient for welding batteries