This is very good useable, clean, antique brass scale weight. It is marked "2 ons" on the top, but actually weighs about 4-5 ounces/20 ml. I am not sure what the ons measure means, but it could be made to fit a certain model balance scale that has a dish the fits on top of one side and the weight of the dish is built into this scale weight. The bottom of the weight is also marked by the maker "C. SCHLIEPER REMSCHEID" and also has a "H" stamped near the maker's mark. The weight is 1.2" diameter and is solid brass with a threaded/tapped hole in the bottom.