OWL Wavetester Fiber Optical Power Meter is an accurate and economical power meter that measures in 850, 1300, 1310, 1490(FTTH testing), and 1550nm. The OWL WT-1 is capable of storing reference values and displaying optical power as a relative or absolute value. The OWL Wavetester Fiber Optical Power Meter features a backlit LCD screen as well as a 2.5mm universal detector port.