Labtro Portable Dissolved Oxygen Meter is a compact device with a 4.3 inch thin film transistor color touchscreen and smart guide technology. It features a dissolved oxygen range of 0 to 99.99 milligrams per liter and a temperature resolution of 0.1 degrees Celsius for precise analysis. https://www.labtro.com/uk/en/portable-dissolved-oxygen-meter/lt-po301