These Bbtalkin non-waterproof headphones are designed to be used with our Advance Unit. You plug the headphone’s 3.5mm audio cable directly into your Advance Unit to establish communication. We recommend using these on land since they are not waterproof. These are ideal for a coach or team member observing from the shoreline or boat. The headset has good quality stereo sound. It covers both ears for less surrounding sound for the user and perfect if you want listen to your favorite music.