Aukai Series
Bone Conduction Series3
https://www.safeswimbuoy.com/custom_130759.html SwimTalk Bone Conduction Swim Teaching Set SwimTalk Bone Conduction Swim Teaching Set SwimTalker Brings Your Teaching UnderwaterThrough bone conduction transmission technology, swimmers can hear the coach's instructions clearly in a noisy circumstance real time, even for athletes with acquired loss or for blind swimmers by using SwimTalker. The comfortable, waterproof receiver easily fits under any swim cap or goggle strap and stays in place. Each swimmer equipped with a headset reveiver can receive individual communications from the coach or can be addressed simultaneously as a team. 
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