Aquatec Duo Alert Aquatec Duo-Alert Air Powered Surface & U/W Signaling Device Scuba Dive Diving Divers BC BCD Gear Aquatec Duo-Alert Air Powered Surface & U/W Signaling Device HOUSE OF SCUBA is an AUTHORIZED DEALER with Full Warranty Signal in U/W and Surface, Volume:Approx. U/W:115-125dB Surface: 125dB Clean in fresh water after use, It's very loud keep away from your ears Three models are available to fit over 95% of the inflators currently on th marketplace