Features: 1.One port outputs 2 wavelengths, entitled with high stability, it is with built?in optical isolator. 2.Working continuously for 46 hours, it can be used for telecommunications repair and cable TV repair. 3.Passing the fiber optic laboratory test, it can also be applicated to other fiber optic measurements. 4.Made of high quality material, being practical and durable, it is entitled with extremely meaningful function. 5.With dual wavelength, being stable, it can be handled for portable use. Meanwhile, it is with universal optical connector. specification:Item Type: Dual wavelength handheld stable light source Wavelength: 1310+1550nm Output Power: -5dB Optical Connector: For FC+SC+2.5mm universal (1.25mm LC optional) Power: Alkaline battery (2 x AAA 1.5V battery, not included) Output Stability: 0.05dB / 15mins; 0.1dB/8 hours Modulation Frequency: CW, 270Hz, 1KHz, 2KHz PackageList:1 x Dual Wavelength Handheld Stable Light Source1 x Instruction Manual NoteBatteries are not included. Please note that the new type and old type of this product will be sent randomly, and make sure you will not mind before ordering.