AQUATEC Scuba Alert Diving Buzzer, Underwater Air Horn, Underwater Buzzer, used item with an international coupler. I am selling this because I can no longer go diving. I used it for approximately 150 dives, and after each use, I disassembled it, rinsed it to remove salt, and reapplied silicone oil to the O-rings, storing it in a closet. I have confirmed that it functions without issue on land. Please consider this item only if you understand that it is a used product.