Fish Finder Tech

Vexilar FLX-20

Overall Rating

When we think about ice fishing, we think of Vexilar. There are a lot of marine tech companies that have dipped their toes into the (very frigid) waters of flashers and ice fish finders, but few have matched Vexilar’s innovations. The company was the progenitor of the original three-color flasher, and they’ve continued to innovate on their core concept. Instead of adding a lot of bells and whistles, they’ve opted to streamline all of the features in their product to three knobs that control the entire unit. The FLX-20, while not as feature-loaded as it’s big brother the FLX-28, is a wonderful flasher that’s going to improve your ice fishing.


  • Super Bright Display
  • 1/2" Target Separation
  • Auto Zoom
  • Low Power Mode (and Low Power Zoom)
  • 6' and 12' Split Screen
  • Fantastic Interference Rejection


  • No CHIRP
  • Flasher Only

Technical Specifications

Frequency200 kHz
Transducer12°, 19°, Pro-View

Display & Interface

What can you do with three colors, a flat screen, and some bright LEDs? As it turns out, you can do a heck of a lot. A quick primer for those not in the know: the green lights mean a signal is weak, the yellow lights mean the signal is medium, and when it’s red, you’ve got a strong signal - a fish waiting to bite. Those three lights are going to be shining in a circle; the bottom will be quite clear, because you’re going to get a bright, big red bar where it’s located.

Vexilar has been in the flasher game for decades and they’ve improved their game a lot in that time. The old flashers weren’t flat screen so only one angler could see what was going on under the water at a time. The FLX-20 can be viewed from a number of different angles so it’s perfect if you’ve got a few buddies out on the ice with you.

There’s a color swap mode on this device that’s pretty nifty; it’s also incredibly simple to understand. Palette one is the green/yellow/red we described above; palette two knocks out the green, and palette three is red alone. In essence, you’re just knocking out the weak signals when you change palettes. When there’s a lot of activity near the bottom or you’re fishing in weeds, this can be incredibly helpful - swap to red only when you’re only looking for the biggest, best fish.

One last note on the display. There’s a night mode on the FLX-20 that dims the LEDs substantially. These things are very bright so the night mode is going to save you a lot of headaches if you’re fishing late into the night or very early in the morning. Press and hold the gain knob to turn it on/off.

The interface on this device is absolutely bare bones and that’s a good thing. There are three knobs that control absolutely everything on the device. The first knob is for gain, the second knob toggles what mode you’re in, and the third knob controls the range of the device. Each and every feature of the FLX-20 can be accessed by either turning or pressing one of these knobs and the controls to let you access all the features are listed to the left of the knobs. You might be a little daunted by this set up at first, but have no fear - it’s really easy to get the hang of everything. Need an extra hand? Vexilar has an operations video for the FLX-20 that you can consult.


Let’s start by analyzing the three main knobs: The gain feature is really straightforward - when you increase the gain, you increase the amount of information the transducer is receiving. Set your gain too high and you’re going to get a jumbled mess of information. Too low, and you won’t be able to see the big catch.

Pushing the gain knob will change the interference rejection which helps if there are other transducers in the water. Finding the right interference rejection can be a bit tricky but if you keep tapping until you stop getting junk data, you’ll be fine. It can take a little time, but it’s well worth doing it right.

The modes knob has most of the features on it. The unit starts on normal mode - nothing special there. You can opt to put it into auto-zoom mode, or 2x auto-zoom mode. With auto-zoom, you get a split screen view on the flasher; the left side is the bottom 6 feet of water in the AZ mode, or 12 feet in AZx2. The right side is the whole water column. This mode is perfect for when you’re fishing in deep water and you don’t need all of the information from the whole water column.

There’s also a low power mode for when you’re fishing in shallow water and you don’t want to interfere with other people’s signals or you’re worried about battery life. What’s more, this device has an auto-zoom and low power mode combo. This mode will tend to only show larger targets so it’s handy if you’re looking to avoid small fry.

The last feature we want to talk about is the range finder. Here’s how it works: you turn the knob to the first setting, 10, and the unit turns on and displays as though it’s in a ten foot column of water The subsequent settings, x2, x4, all the way up to x10 are multipliers for that initial ten feet, maxing out at 100. Astute readers will notice that this doesn’t quite make sense as the maximum depth listed in the specs tops out at 300! All you need to do is switch to deep water mode to solve this problem. Turn the unit off, push and hold the gain button, then put that range knob to 10. This applies a x3 multiplier, so your ten foot setting is actually 30 feet, the x2 setting is 60 feet, so on and so forth to 300 feet.


There are three different transducers that work with this device: the 12°, the 19°, and the ProView. All of these transducers are made with barium titanate, a cold resistant metal that makes Vexilar transducers incredibly durable compared to some of the other transducers on the market. These “Ice-ducers” all come with a floatation device that keeps them stable and upright in the water.

The 12° has a fairly narrow cone; you’ll only be able to see fish within 12 degrees of the transducer and it gives you depths of up to 45 feet. Conversely, you get a much wider cone with the 19°, but it can only reach depths of 30 feet accurately. These options are certainly fine if you know you’re going to fish in relatively shallow waters most of the time but they don’t take advantage of the FLX-20’s wide range of depth settings.

The ProView transducer is where it’s at, in our humble opinion. The ProView takes advantage of the gain knob to change how wide its cone is. In the lowest setting, it’s a 9° cone, and as you increase the gain, the width of the cone expands; that means it can more or less take the place of the 12° or 19° transducers without any trouble at all.


There are three different packs you can get with your FLX-20. The first one, the Genz pack, is about as basic as you can get - it’s more or less a really rugged piece of plastic that you can attach your flasher to. It, and all the rest of the packs, come with 12 volt 9 amp hour batteries. Everything is exposed on the Genz pack but it’s customizable because it’s so simple - feel free to screw or drill in whatever attachments you want.

The Pro Pack is a bit more refined than the Genz pack; it comes with a rod holder and a cable management system though the battery remains exposed. You’ll also get a tackle box with the Pro Pack, which, while unexciting, is nice if you’re short on tackle boxes.

The Ultra Pack is much like the Pro Pack but it features a master on/off switch for the battery as well as a digital depth display to tell you exactly how many feet of water you’re fishing in; handy, because unlike the FLX-28, the FLX-20 doesn’t already have one integrated.

The Bottom Line

The FLX-20 is a wonderful unit. The design is spartan to be sure but it’s built to last and there’s a lot of innovation in the unit given how simple the interface is. It lacks the plug-and-play auto range finding features of its new brother, the FLX-28 and it doesn’t have quite as many features, but if you’re willing to put the effort into learning to navigate the system, you’ll be rewarded with a great flasher for a very reasonable price.

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