LC/APC Singlemode 9/125um Fiber Optic Loopback Test Plug These compact, high-return-loss loopbacks are already popular for quick network testing and certification. Fiber Loopback is designed to provide a media of return patch for a fiber optic signal. Typically, it is used for fiber optic testing applications or network restorations. For the testing applications, the loopback signal is used for diagnosing a problem. Sending a loopback test to network equipment, one at a time, is a technique for isolating a problem. Specifications Type: Loopback Module Test wavelength: 1,310 and 1,550nm Fiber: Bending insensitive Singlemode 9/125 Connector: LC/APC Insertion loss: Typical: ≤0.20dB Maximum: ≤0.30dB Return loss: UPC: ≥50.0dB Repeatability: ≤0.10dB Interchangeability: ≤0.20dB Durability: ≤0.20dB typical change, 1,000 mating Operating temperature: -20 to +70 degrees C Applications R&D Fiber labs Telecom testing FTTX testing Patch panel applications Equipment interconnection