Surf hat with waterproof boom microphone by BbTALKIN. This surf hat headset is designed to be used with our Advance Unit. You plug the boom microphone’s 3.5mm audio cable directly into your Advance Unit to establish communication. The microphone and speaker piece on the boom microphone are completely waterproof. The design of the boom microphone allows the flexibility to change out either the microphone piece or speaker piece if it becomes damaged over time.