very low cross-axis sensitivity is designed to measure both the direction and the magnitude of Earths magnetic fields, from milli-gauss to 8 gausses. Honeywells Magnetic Sensors are among the most sensitive and reliable low-field sensors in the industry. Note: Sometimes markings on these boards vary slightly (e.g. Some may be labeled HW-127 instead of GY-273 even though they are otherwise identical). Applications: Auto and personal navigation. UAV systems. Robotic navigation. Location-based services (LBS). Features: 1-2 degree heading accuracy. A range of -8 to +8 Gauss. Communication: IIC communication protocol.