FAR-REACHING DISTANCE: 30mW visual fault locator can output very bright red light, up to 30 KM, and works great to check for old, misplaced cable or any damages inline of the cable. | UNIVERSAL ADAPTER: 2.5mm universal connector of the detector is compatible with ST/SC/FC female (panel) to meet different needs, can be used to test single mode and multi-mode cables. Very practical for telecommunications engineering maintenance personnel. | CRASH-PROOF & DUST-PROOF DESIGN: The head of the VFL pen is made of reinforced stainless steel. The body is made of aluminum. Resistant to high impact and prevents ESD damage. The precision design is effectively dust-proof. | UPGRADED DESIGN: The surface design of metallic matt paint is easy to clean, and the sliding switch design facilitates quick and easy control of the light. Compact and lightweight design is portable and easy for field test. | SATISFACTORY AFTER-SALES: Our fiber optic cable tester provides 30 days no reason for refund and one year warranty, you have no risk of trying, if you have any questions or after-sales questions, please feel free to contact us, we will give you a satisfactory answer.