Features: It can easily and accurately detect and locate fiber breaks, poor connections, bending or cracking. The detector will emit a 650nm bright light for fiber tracing, breaks or faults in the fiber will refract the light. Pen-type design with pouch make it portable, easy to check fiber faults with visual fault locator, rugged,Dust-proof design keep fiber connectors clean. The 2.5mm universal connector of the detector is compatibly designed for ST, SC, for FC interferes both in circle and square shape of different fiber optic cables.Test for both single-mode and multi-mode cables. This 10mW visual fault locator with battery output strong red light goes 10 kilomters far, high effective power circuits allows for stable power. brand new and high quality Small size and lightweight, it is portable and easy for field test with multiple functions such as constant output power, lower battery warning, long battery life and long distance detection. Package Includes: 1PC x Fiber Optic Cable Tester Specifications: Material of shell: Alum-alloy Product name: red light pen Output optical power:>1-10-20-30mW Output wavelength: 650nm Fiber Adapter: 2.5mm Universal Connector Operating temperature: 0~+60 degrees C Storage temperature: -20~+70 degrees C Battery type: 2 AA alkaline batteries Battery life: 13 hours Appearance: approx. 175x26x26mm/6.89x1.02in note: Size for manual measurement, there may be a 0 to 2 for cm error, belongs to the normal phenomenon. And due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you!