Review on 🔦 SPEEDWOLF Portable FTTH Fiber Optical Power Meter (-50dBm~+26dBm), Handheld Fiber Cable Tester Tool with 30mW 30KM VFL and SC+FC Adapter for CCTV CATV Engineering Maintenance by Josh Schweitzer

POWER METER: At this price the power meter is not the most accurate but can be used for reference measurements and dB loss between two points. I find that the power reading is a few dB off compared to a more professional power meter. EDIT: I've now read the manual and figured out how to calibrate this meter. There is a tiny switch hidden in the battery compartment. I calibrated it following the step-by-step guide in the manual and everything is fine now. You need to find a reference light with a known power value and calibrate it to that light. Now this meter rocks. VFL: VFL is powerful and works very well. The fact that it uses a user-replaceable, low-cost 18650 Li-Ion battery (included) or connects to a standard USB 5V power adapter (included) and mini-USB cable (included included) can be connected, makes it reliable and dependable. The battery lasts about 15 hours and can be set not to turn off until it's fully discharged. I left it plugged in for over 24 hours and came back still glowing brightly. At this price point this is a great tool for any fiber optician and it has some features that are more versatile than devices. costs 5 times more.