This is a water-activated Alkaline light that activates automatically when it comes into contact with water, and it can be turned off manually if needed.
DAN W4 is a SOLAS-approved single compact flashing unit where the light is emitted through an ultra low profile dome, which makes the light less susceptible to damage during evacuation.
Regatta’s life jackets for the professional market have an adapted fastening device for lights in the front of the life jacket.