UEi C125 Kit Combustion Analyzer measures flue temperature, oxygen, carbon monoxide (CO), differential, ambient carbon monoxide (CO), and differential pressure. This combustion analyzer calculates carbon dioxide, gross/net efficiency, excess air, CO air free. The Eagle 2 C125KIT - is 4 instruments in 1. Designed to offer advanced system analysis and productivity this kit includes the Eagle 2 Combustion Analyzer. This multi-functional instrument is a superior combustion analyzer with unmatched simplicity and a unique combination of features to enhance a technicians efficiency and safety. The UEi C125 Kit is perfect for combustion efficiency analysis but also doubles as a differential thermometer, differential manometer, and an ambient CO detector.