The Northern Lights Rattle Reel is constructed of fluorescent acrylic plastic, not wood or plain nylon plastic. Embedded inside are two UV LED light discs that activate ON as soon as a fish pulls the line from the wheel/reel. This light is triggered by a battery powered magnetic switch embedded in the mounting arm of this unit. The set point is fully adjustable for any depth you may be fishing in. Simply place the clip-on magnet in front of magnet permanently placed in handle once the depth has been set. This will operate on 12VDC power via battery or hard wired to 12VDC car battery, which most fish houses have operating already for heat and lights. In addition to the UV LED lights which already glow, we also use a bell for sound alerting.