This set includes two brand new FC Fiber Optic FC/UPC-3DB Attenuators. These attenuators are portable and reliable, making them an ideal choice for those who require accurate attenuation in their fiber optic network. They have a single-mode wavelength parameter of 1310~1550 NM and an accurate attenuation of <0.5db. The connectors are FC/UPC, with a core insertion type of ceramics. These attenuators come in a convenient bag package and have been tested and measured for geometry. They are suitable for use in a variety of applications, including networking and computer cables and connectors.