stereo depth output in mm

From stereo depth node graph (https://docs.luxonis.com/projects/api/en/latest/components/nodes/stereo_depth/#internal-block-diagram-of-stereodepth-node), the unit for the depth is in [mm]. But in my case, this number is very big and does not seem to be in mm. Are there any settings that I need to do to get the right values? Any example of this would be helpful. Thanks!