A SOLAS-approved strobe light with a built-in water activation feature that will automatically activate once submerged4 activation functions, toggle between the armed mode for automatic water activation, ultra-bright strobe light or the SOS strobe to visually alert Search and Rescue of your location, then toggle to the Steady-On feature for close up recovery operations.Cool white color LEDs produce a 360 degree beam of light that is over 41 candelas bright allowing for visibility of over 3.5 milesEnergy efficient microprocessor and redesigned electronics, with a single set of AA alkaline batteries, the Firefly PRO will continuously strobe for over 56 hours or use the Steady-On feature for 28 hoursCool white color of the LED strobe has no yellow tint allowing the light to be seen at greater distances4.4" x 2.2" x 1.2", 2.39 oz (68 g) (without batteries)SOLAS - Approved, USCG - Approved, IMO LSA - Pending, CE - Pending