Features: 1Maintenance Capability: The visual fault detector 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: This test pen uses a non contact connection that does not damage the end face of the fiber and transmitter, and the output power is not affected by voltage fluctuations. 3Stable 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: Small size and light weight are the features of this test pen, you can carry this test pen with you when you need it. 5Energy Saving Design: This test pen has an energy saving design that allows the test pen to have a greater battery life for longer use. Package included: 1 x Red&nbspLight&nbspPen&nbsp 1 x Pen&nbspPouch 1 x Lanyard 1 x Ceramic&nbspCore&nbsp 1 x Instruction&nbspBook&nbsp &nbsp