We keep close tabs on the food we eat, the amount of water we drink, and how active we are. Yet the most essential component of day-to-day life — the air we breathe — hardly gets more thought than a glance at the thermostat or weather app. The Jacob Jensen Air Quality Monitor is out to change that. It measures levels of pollutants like VOCs, nitrogen dioxide, and carbon monoxide, distilling them down to an Air Quality Index number that it displays on its screen, alongside the temperature and humidity. It has a built-in battery that lets you take it wherever you are, a light on the bottom that gives you an at-a-glance look at the air quality (green is good, orange so-so, red is bad) and is made from durable ABS and polycarbonate so it can accompany you on long trips with ease.