The Handheld Optical Power Meter is a precision, durable portable instrument specifically designed for theinstallation, operation and maintenance of fiber optics. With a compact shape, the background display andautomatic shutdown function of the switch can be selected. Ultra-wide optical power test range. Accurate testaccuracy and user self-calibration function and multi-purpose interface design, while linear index (mW) andnonlinear index (dBm) are displayed on the same screen.