The FL-8 and FL-18 are depth finding and fish finding flashing sonar units made by Vexilar. They are a great help to all fishermen, but especially ice fishermen, as they produce real-time feedback of what's going on directly under your hole. They show you the bottom, and anything between the surface and the bottom, including structure, your lure, and any fish within the sonar cone, in a three-color LED scheme. If you want to find out more, go to vexilar.com and research. If you're an ice fisherman, or fisherwoman, for that matter, they are a great help, mine is on the fritz and I feel blind with out it, and I only had it a year, after 20+ years of fishing without one! If you love to fish, they are something you should research. It's very hard to explain what they look like from a picture, but the vexilar site does a pretty good job, and I gave a comparatively poor description of their capabilities.
Selmer