Fiber Ranger is lightweight, rugged, dustproof and waterproof; in software, it has three brilliant functions. One is Automatic Power Control, which automatically test and adjust the best power level according to the real test environment; second is Automatic Pulse Width Selection which automatically select most suitable pulse width according to the real test distance. Third, it has built-in 650nm VFL, with which it can detect the fault from 1-15km and finally realize the one-dead zone test over the full range.