[High efficiency]Easy identification of fiber breakpoints, poor connecttions, bending or cracking. for finding the right fiber to splice or quickly finding a break. 30mW Visual Fault Locator emit a 650nm red light for fiber tracing, fiber routing and continuity checking efficiently. Breaks or faults in the fiber will refract the light, creating a glow around the faulty area. [ Functions] The fiber optic tester is for field tests because of multiple functions such as constant output power, multi-interface adaptation, low battery warning, long battery life, and long-distance detection. Super and uses convenient AA battery. [Widely USed]2.5mm Universal Connector - the connector of the detector is compatibly designed for ST, , , LC interferes both in and square shape of different fiber optic cables. [Long Output Distance]The 30mW visual fault locator has a strong output power, can output a strong red indicating light, up to 20-30 kilometers. The high-efficiency power supply circuit ensures a stable power supply. [Crash-proof and Dust-proof Design for Pen Head]It Is Designed With Stainless Steel Head And Aluminium Body To Prevent Crash And Dust, And The Case Ground Design Prevents ESD Damage Efficiently. Batteries: Two 1.5V batteries (not included) type: A Colour:green + black Material:Aluminum alloy Package Contents: 1 set x fiber identifier Only the above package content, other are not included. Note: Light and different displays may cause the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.