Mini visual fault locator FVFL-301 with secret key function is a small but powerful and more secure test tool for optical fiber and cable. Its output power is up to 10MW. It can be used to locate sharp bends & breaks in jacket or bare fiber within 12km. It can also be applied to identify the connectors in patch panels and identify the fibers during splicing operation. Selecting continuous wave output mode for stabilizing fault lighting or flashing output mode can make fault location easier.