1Ergonomic Design: Aluminum alloy body with non slip handle, comfortable in hand. Ergonomic design, compact and portable, easy to pick up with one hand. Replaceable ceramic tube core, more convenient to use. 2Three Interfaces: Support three interfaces to meet different needs, with standard 5mm universal connector, can support FC interface, SC interface, ST interface. 4Integrated Chip: This test pen uses a powerful light source integrated chip, integrating power management, signal modulation and switch control. 5Steady Performance: The performance of this tester is very stable, with a stable output power, which means that it can improve the efficiency of the user. 3Open Cover Type Pen Tip: Our test pen comes with a protection cover and uses an open cover type pen tip to prevent the head from getting damaged by dust.