NF-908 series contains an optical power meter for fiber optic cables and a continuity tester for RJ45 network cables. And NF-908S for an accurate RJ45 network. Optical Power Measurement - Can measure single-mode wavelengths like 1310, 1490, 1550, and 1625nm with measurement range from -60 to +8dBm. With a strong light source, it is easy to penetrate long-distance. Please read and learn safety instructions before use or maintain the equipment. Pls avoid the laser directly to your eye when it works. Its compact design ensures portability, while the user-friendly features like automatic shutdown and compatibility with FC, ST, and SC interfaces enhance. Optical power meters and detectors have been served by Newport for over 30 years.