Excellent condition, working and complete. Includes a new Fisher Scientific platinum-iridium ring #14-812-5 and a 20 pages instructions manual (pdf). Unit is a Fisher Surface Tensiometer model 20, surplus from a medical laboratory. Very clean, light surface scratches only. Portable, measures 10 X 9.5 X 12.5 inches and weighs 18 pounds. The included platinum-iridium ring has its original wooden box and measures approx.: 20mm diameter, 59mm total height, 0.034 oz weight. This tensiometer is used to determine the apparent surface tension and interfacial tension of liquids. Employing the ring method to achieve speed and accuracy, the instrument is applicable to many educational, biological, medical and industrial determinations in connection with water, petroleum products, detergents, pharmaceutical materials and other substances.