I based the handle on the tote of a Stanley Jack plane figuring it would be a more comfortable and controllable push block. the handle is old growth cherry i’ve had laying around my shop for about 15 years, finished with buffed bee’s wax. the lower part is just pine, held on with a sliding dovetail, so it can be changed out for different widths, and replaced if I have an errant cut. the ball in the center has a threaded insert in it which drives a threaded rod down into the dovetail to lock it. I will never cut a quick plywood pushblock again!!