• Description
  • Why Buy From Us

GNX™ 21 Marine Instrument with Inverted Display - 4"

Marine Instrument with Inverted 4" LCD

  • Large, easy-to-read white or color digits on a black background for high visibility in low-light or darkness; choose from 7 customizable backlight colors
  • Glass-bonded display with anti-glare lens avoids fogging
  • Fully customizable user profiles for sail or power boating to display most important marine and vessel data
  • Low power consumption (25 mA) with 350 mW (no backlight)/400 mW (mid-level backlight)
  • 5 display configurations plus gauge and graph mode to display depth, speed, wind and 50+ marine and boat parameters

The easy-to-read GNX 21 marine instrument has an inverted display with white or color digits on a black background that clearly shows depth, speed, wind and 50-plus marine and boat parameters. Its glass-bonded display with anti-glare lens coating provides excellent daytime and nighttime readability with high-contrast digits scalable up to 36 mm.

The GNX 21 is the first glass-bonded marine instrument with a combination of directly driven LCD segments and a dot-matrix field to display graphical information. Its low power consumption - (25 mA) with 350 mW (no backlight)/400 mW (mid-level backlight) - is perfect for use on sailboats, and provides a valuable instrument for cruising and fishing. Fully customizable user profiles display wind, depth and speed data. Plus, the GNX 21 includes an auto-scroll feature that rotates through data screens for hands-free operation. It can be installed with the included low profile flush mount or an optional flat mount for the ultimate glass helm solution and custom look for your boat.

Easy-To-Read Display

Unique high-contrast hybrid display features large, easy-to-read digits scalable up to 36 mm tall. Offers excellent clarity in direct sunlight, at dusk, or at night. The dot-matrix section can show additional details and/or graphical information.

Glass-bonded Display

Glass-bonded display helps prevent fogging, and the anti-glare lens finish increases visibility.

Customizable Color Digits

Choose from 7 different backlight colors, or even create a customized color, to achieve the screen that provides optimum readability for you.

Customizable User Profiles

Fully customizable user profiles allow you to choose from 5 available display configurations for sailboat or powerboat user-profiles: single, dual and triple function, plus gauge and graph mode to display wind, depth and speed data, or customize the pages to display the marine and boat data that is most important to you.

Auto Scroll

Set your display to automatically cycle between pages at a speed you set for convenient, hands-free operation.

Low Power Consumption

Perfect for sailors who want to sail for long intervals without having to run a motor or generator to charge batteries. The GNX 21 uses only 25 mA with 350 mW daytime usage, requiring no backlight and just 400 mW with a mid-level backlight setting at night.

NMEA® 2000

Monitor more than 50 marine and boat parameters, including GPS speed, water depth and temperature, wind direction, and wind speed from the NMEA 2000 bus. You can also add a NMEA 0183 device using the optional 7-pin bare-wire power/data cable.

In The Box

  • GNX 21
  • Trim piece snap cover
  • Protective cover
  • Flush mount gasket and hardware
  • NMEA 2000® T-connector
  • NMEA 2000 drop cable
  • Installation instructions
  • Documentation

WarningWARNING: This product can expose you to chemicals which are known to the State of California to cause cancer, birth defects or other reproductive harm. For more information go to P65Warnings.ca.gov.

Specifications:

  • Shape: Square
  • Screen Size: 4"
  • Instrument Function: Multifunction
  • Box Dimensions: 5"H x 9"W x 10"L WT: 2.95 lbs
  • UPC: 753759120962

Owner's Manual (pdf)
Brochure (pdf)

Why Choose Green Vista Living


At Green Vista Living, we’re passionate about providing top-quality renewable energy and eco-friendly products that not only enhance your life but also help protect the planet. We’ve built our business with one mission in mind: to be the go-to destination for renewable energy solutions, outdoor gear, and off-grid supplies. When you shop with us, you’re not just getting innovative products—you’re joining a community that’s committed to sustainability.

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As a small, dedicated team, we care deeply about your experience. Unlike large, faceless online companies, Green Vista Living offers a personal touch in everything we do. We're here for you from start to finish—whether you need product advice, support after a purchase, or just have questions. Our knowledgeable customer service team is always just a phone call or email away, ready to assist you in any way possible.

We Share Your Passion for the Planet


Our love for the outdoors and sustainable living runs deep. Most of our team hails from the mountains of Colorado, where renewable energy and the environment are part of daily life. So when you call Green Vista Living, you’ll speak directly with an expert who understands both the technical side of renewable products and the lifestyle they support. Whether you’re looking for solar generators, EV chargers, or any of our eco-friendly offerings, you can trust us to guide you with expertise and passion.

Trusted Industry Experts


Our close partnerships with the best brands in renewable energy and outdoor gear give us insider knowledge that you won’t find anywhere else. We’ve taken the time to carefully select products that stand out for their quality and reliability. At Green Vista Living, we believe in understanding our products inside and out so that we can help you make the right choice with confidence.

More Reasons to Love Green Vista Living


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At Green Vista Living, we aim to make your renewable energy and outdoor experience as seamless and enjoyable as possible. With our unmatched customer service, expertise, and dedication to quality, you can shop with confidence, knowing you’re supporting a company that’s as committed to the planet as you are.

Frequently Asked Questions

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