It's a handle and display in the same piece. Lift the little knob, and the desk goes up; push it down, and you guessed it, it goes down. Within the knob is a display that reads out the height as well.

The alder from earlier came in use to serve as a front edge for the plywood and a groove to hold the sliding piece of plywood that extends and retracts as the desk goes up and down. Regular old ...