The SparkFun Qwiic and Adafruit STEMMA QT systems are an interchangeable ecosystem of I2C sensors, actuators, shields and cables that make prototyping faster and less prone to error. All Qwiic and STEMMA QT-enabled boards use a common 1mm pitch, 4-pin JST connector. This reduces the amount of required PCB space, and polarized connections mean you can’t hook it up wrong.