This brick contains DHT11 is a digital temperature and humidity sensor. The 3 pins are GROUND, Vcc (3.3V-5VDC) and SIGNAL. The SIGNAL pin connects into any Arduino digital input.What are Electronic bricks?Documentation:SchematicSCH_IM120710021.pdfDatasheetDS_IM120710021.pdfLady Ada has a great tutorial and library for the Arduino