Features: 1.Easy identification of fiber breakpoints, poor connectors, bending or cracking. 2.It features a red design, a universal connector and an accurate measurement. It locates fibers, finds faults, verify continuity and polarity. 3.It is wide used in telecommunications engineering and maintenance, maintenance, cabling System and other fiber-optic project. 4.Red light output distance 12.4mi, high effective power circuits allows for stable power. 5.The pen body is designed with sliding cover switch, which can control the use state of the red light pen at will. 6.It is designed with aluminum alloy material to prevent crash and dust. Specification: Condition: 100% Brand New_x000D_ Item Type: Fiber Optic Cable Tester_x000D_ Material: Aluminum Alloy_x000D_ Color: As Pictures Shown_x000D_ Model: ht-20_x000D_ Power: 20mW_x000D_ Measuring Range: Approx. 20km / 12.4mi_x000D_ Power: 2 x AA batteries (not included)_x000D_ Uses: Detect fiber jumpers PackageList: 1 x Fiber Optic Test Pen1 x Ceramic Core1 x PU Cover1 x Rope1 x Chinese/English Manual Note: Each red light pen gives an extra ceramic core. When it needs to be replaced, it can be replaced by screwing off the metal pen head (ceramic core belongs to fragile articles, and can not be installed and operated by brute force).