MK2E2
The MK2E2 is an 11-DoF IMU that pairs an optical gyroscope built on a photonic integrated circuit with MEMS accelerometers, magnetometers and inclinometers. 78 x 63 x 36 mm, 230 g, 2 W. RS-422 or CAN-FD at up to 500 Hz.
Choose it when GNSS drops out for minutes rather than seconds and heading error is what breaks the solution: heavy machinery and agriculture under canopy, tunnels and pits, marine, and UAVs operating where GNSS is contested. Angle random walk is 0.03 °/√hr against 0.06 on the MK2M2, and the optical axis has no moving mass to walk under vibration. On a 21 minute Montreal road test with GNSS position denied, the MK2E2 finished 5.7 m from truth.
Every unit is factory-calibrated for offset, scale factor and misalignment, plus magnetometer hard and soft iron. In the field you re-run gyro offset at startup and the magnetometer after each re-install.