Airthings 2930 Wave Plus - Radon & Air Quality Monitor, Battery Powered (CO2, VOC, Humidity, Temp, Pressure)

Why it's worth it

The Wave Plus tracks radon continuously alongside CO2, VOCs, humidity, temperature and air pressure. A wave of your hand lights it green, yellow or red, so anyone in the house can check the air without opening an app or knowing what pCi/L means.

Six sensors in one battery-powered puck cover most of what goes wrong indoors. Radon is the headline, but CO2 tells you whether a finished basement or a closed home office is actually getting fresh air, and VOC readings pick up fumes from paint, solvents and cleaning supplies stored downstairs. Humidity helps you interpret both. If you'd otherwise buy two or three separate gadgets, this consolidates them.

The wave gesture is the feature that makes it a household device. Hold your hand in front of it and the ring glows green, yellow or red. No phone, no login, no interpreting a number. In a house where one person cares about air quality data and everybody else just wants to know if things are fine, that's genuinely useful. Kids get it immediately.

From our review of 7 radon detectors and test kits, by David Sinclair, Managing Editor

What we like

• +Six sensors in one battery-powered puck cover most of what goes wrong indoors
• +The wave gesture is the feature that makes it a household device
• +Battery power means you can put it where the radon actually is
• +The app builds a long trend record that reveals seasonal patterns

What to know

• –Bluetooth only, and the fix costs extra
• –There's no alarm of any kind
• –It costs more than our top pick while measuring radon less sensitively