Mid-drive parts.
This mid-drive uses two freewheels mounted on a bearing. (from left to right): At the left is the track sprocket that drives the rear wheel. The large 72-tooth sprocket is for a #25 machine roller chain and is the step-down gear for the motor. It's mounted to a single-speed freewheel. Next is a spacer, then the 7-speed freewheel that is driven by the crank. At the right is the 1.37"x24tpi bearing onto which the prior sprockets and freewheels are mounted. At the bottom are the 5 1/2" bolt and miscellaneous hardware used to mount the double-freewheel to the frame. This was an early configuration for this mid-drive.