These were exactly as advertised. Bolt is 3/8 diameter 1 long, with standard threading. And if you like big knobs, these are the knobs for you. About 2.25 diameter, 1.5 tall, with the stem being roughly 7/8 tall and 7/8 in diameter. A little bigger than I'd like for aesthetic reasons, but they seem very well made and they did fit my device fine. Very easy to grasp with the whole hand and turn. The finish is gloss black, reminiscent of Bakelite.
Rating: [5 of 5 Stars!]