The Plume Labs Flow 2 sensor is a small, wearable air quality device that provides real-time measurements of PM1.0, PM2.5 and PM10 mass concentrations, VOCs and NO2 concentrations. Data can be exported using a phone application for Android and iPhone via Bluetooth and has been visualised on York Air Map for the public to see. Citizen scientists attach the sensor to their bicycles and collect data during daily commutes.