Looking for a back-to-basics heads-up display, the Sherox 3.5-inch HUD is a bit pricey, but it offers minimal data so drivers can focus on driving. Capable of displaying four automotive parameters on the car's windshield, its small casing does not block the forward view or distract from all that is going on around it.

The Sherox 3.5-inch HUD, priced at $70, is a little wonder that gives you basic information about your car while driving. In contrast, the $40 Sherox C100 has a foldable screen but displays even less data.

Like many competing products, the Sherox 3.5-inch HUD sits flat on the dashboard and projects data upward onto the windshield. The smallest and lightest add-on heads-up display available, the Sherox 3.5-inch HUD measures 2.8 x 1.9 x 1.0 inches and weighs only 1.4 ounces.

The HUD does not come with any sort of adhesive strip to attach it to the dashboard. Therefore, it is necessary to come up with a solution that will keep it from bouncing around on rough roads.

Despite its name, the device's screen is 3.0 inches monochrome and is no match for a color heads-up display. It is bright enough to display data on a windshield, but is best paired with an included reflective screen that can be mounted on the inside of the car's windshield. However, it does not have a built-in projection screen like the Pyle PHUD180BD.

The Sherox 3.5-inch HUD has no on/off switch, is controlled by a small wheel, and gets its power and data from a port on top; a 69-inch flat OBD cable carries both power and data to the unit and can be pushed into a gap in the dashboard. In other words, if a semi-professional were to install the unit, the cable would almost disappear.

On the downside, while other HUDs display dozens of operating parameters, the Sherox 3.5-inch HUD sticks to the basics. The only things that can be displayed are speed (MPH or KPH), engine temperature, battery voltage, and mileage. Its simplicity is refreshing, but it lacks essentials like engine RPM; the Sherox 3.5" has an OBD failure warning icon, but an OBD-II scanner is needed to know what the problem is.

The HUD's built-in light sensor can automatically control the brightness of the display or adjust it manually; the Sherox 3.5" HUD not only warns that a gear shift is imminent, but also that the battery is not at the proper voltage, that the car the car is going too fast or overheating.

The Sherox 3.5-inch HUD can be used with most vehicles that have an OBD or EUOBD port for diagnostic data. Unlike some competing products, it will also work on hybrid vehicles, but requires a different setup routine. However, it cannot be used with fully electric vehicles or many trucks.

Plugging the Sherox 3.5-inch HUD connector into my car's OBD port was quick and easy, and the unit activated instantly. Like many others, the connector is too short to easily remove, so you may need to resort to pliers.

The device includes a one-year warranty, but that documentation, printed on a single 3.9 x 2.8-inch sheet of paper, is sadly lacking. It only shows the main icons, how the configuration wheel works, and a list of features.

After plugging the cable into the OBD port of my 2014 Audi A4 AllRoad, it took a second for the Sherox 3.5-inch HUD screen to activate. Once I stopped the car, the device automatically turned off. The lack of a power switch is a major drawback, and like the Pyle PHUD180BD, it does not have the ability to remain on for a period of time after the car is shut down.

On the road, the Sherox 3.5-inch HUD displayed basic parameters. Vehicle speed was displayed in large white numbers and projected on a large reflective screen.

Sadly, its output was barely visible on the car's bare windshield, despite Sherox's documentation claiming that a reflective screen was not necessary. However, the output of the Pyle PHUD180BD HUD is bright and easy to see at a glance.

Small and basic, Sherox's 3.5-inch HUD is able to communicate important vehicle data to the driver without being in the driver's line of sight. The monochrome display, which can show only a few parameters, is lacking compared to the large color displays of other HUDs.

It also lacks brightness and requires the use of the included reflective screen for use on public roads. Still, the Sherox 3.5" is a good addition to any car on the road today, although it may still be too basic for the curious driver.