1Break Finding Ability: The visual fault locator is specifically designed to maintain fiber optic cables and lines, for locating defects on cables and cables, visually searching for fiber breaks and using the device. 2Non Contact Connection: The output power of the test pen is not affected by voltage fluctuations. And the pen uses a non contact connection that does not damage the end face of the fiber and transmitter. 3Steady Performance: The performance of this test pen is very stable, with a stable output power, which means that it can improve the efficiency of the user. 4Easy To Carry: This pen tester is small size and light weight, and the features of this test pen is great. And you can carry this test pen with you when you need it. 5Energy Saving: This red light test pen has an energy saving design that allows the test pen to have a greater battery life for longer use.