Get started with the DGS4 89x-Series I2C Gas Sensors quickly. The DGS4 Single-Gas Developer Kit (899-100) pairs a DGS4 Pin Adapter with an Adafruit QT Py Shield, letting you evaluate any 891- or 895-Series sensor over I2C with the open-source firmware. See the DGS4 89x-Series Developer Kit User Guide for details. Sensors sold separately.