These refractometers offer exceptional optical design and improved image resolution with high contrast for easy viewing of scales. All reflection-coated glass optical components, including a 7x eyepiece, have been developed to improve illumination and shadowline contrast. Black housing improves image quality by reducing stray light. Optics and instrument scales are sealed inside, safe from harsh external conditions. Measure concentration of fruits, beverages, and canned goods; total solid content of syrups, vinegar, and sauces; or check the quality of vegetable, fruit, and grass tissues It is basically a NEW unit, but the manual and outer box have some scuff marks. The Refractometer works great! 0.0-50.0% Brix, +/-0.25% Brix Water-resistant IP67-rated design is ideal for stringent environments Rugged, impact-resistant Xenoy polycarbonate housing withstands repeated drops HUGE Automatic Temperature Compensation range - 0'F-104'F