The waldo looks like an old audio turntable, the kind that played disc records, with the vise set up under a transparent dust cover. The arm itself is just over a centimeter long, swinging out on what would’ve been the tone arm on one of those turntables. But I don’t look at that when I’ve clipped the leads to my stump; I look at the scope, because that’s my arm there in black and white, magnification 40 x.