The Bigblue FF4X5 aluminum LED dive light delivers a stunning bright light beam and can come with an optional Automatic-Flash-Off function. The Bigblue made of durable anti-corrosive aluminum alloy anodized, and uses a magnetic rotary switch ring. The light comes with a solid aluminum lantern-stye handle, a standard one-inch T6061 aluminum ball joint, and an adjustable lanyard. Bigblue Auto-Flash-Off (AFO) is a photo-cell sensor located on the front of the light that recognizes when your camera strobe flashes and the sensor turns off your light for one second