GY-651 HMC5883L BMP085 MWC Four-axis Flight Control Sensor Electronic Compass Atmospheric Pressure Module.
Power supply :3-5v (internal low dropout regulator)
Size: 13.5mm * 15.8mm (pin spacing standard 2.54mm)
Communication modes: standard IIC communication protocol
Magnetic field range: ± 1.3 to ± 8.1 gauss
Pressure range :300-1100hPa