The InvenSense MPU-6050 sensor contains an accelerometer and a gyroscope in a single chip. It is very accurate, this sensor is used in self balancing robots, drones, smartphones, etc. The sensor uses the I2C-bus to interface with microcontroller.
This is a 4WD IG42 single bearing platform that is setup for outdoor navigation/positioning. A full array of sensor options including an IMU, motor encoders, and a Garmin 18x GPS that can provide position feedback with up to 3 meter accuracy.