Fast and accurate. No need to wait for warm-up, just plug and play. +/- 5% uncertainty, -70 to +6 decibel meter measurement, relative power calculation, calibration function. Durable. Sensitive chip and solid internal structure. Low power consumption, continuous work for 48 hours. (Excluding 3 AA batteries) Transparent blue screen. Details mean professional, unique results or information display to ensure a satisfactory user experience. 6 Wavelength and light source. 850/1300/1310/1490/1550/1625 nanometer + 5km red light locator + SC//ST adapter. Meet most of the requirements of CCTV communication engineering maintenance. The convenient size is right. Material:plastic colour:blue Package Contents: 1 x Optical fiber power meter Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.