Machinist mini screw jacks, 3 for you to choose from, 1 1/2 inch diameter at base, close to 3 inch, open up to 4 1/2 inch, not marked that I can find, they look just like a Starrett Little Giant and I have had them unmarked also but they were not red. Very good condition, work like they are supposed to. Choose from the 3 for $10.00 cash each, phone calls only, no text.