19J605 up for sale is a new old stock photo camera telescope of old radio knurled knob , this has the classic spun aluminum face and is made of black plastic with course knurled outer diameter , this outer diameter measures 2.110 just under 2 1/8 inch the total width is 0.640 just over 5/8 the back has a pressed in aluminum bushing that has a inner diameter of 1/4 and has 2 set screw s to hold it on and these set screws are accessed from a holes  in the side , nice handle for many vintage applications, comes as shown in the photos ,