RailLight Premium features Fastsolar quick charging technology and is fully marinized for use around salt or fresh water. The solar cell is epoxy coated and the dome and post are made of stainless steel. The Polycarbonate Fresnel lens amplifies light 10 times for up to two mile visibility. Comes with QuickMount System to provide for three separate ways to mount RailLight. Automatic light sensor is built in to shut off the light during the daytime for optimal charging. Four bright white LEDs last up to 8 hours after dark on a full charge.