Features: Engineered for telecom grade performances, this multimode 50/125μm fiber loopback ensures reliable, low loss signal transmission in high demanded networking environment. Its pocket design features precise OM3/OM4 compatibility and minimal insertion loss for consistent optical performances. Ideal for networking administrators, telecom engineers, and data center technicians requiring stable short distance fiber optical connection solution. Optimized for server farm crossing connection, and telecom infrastructure maintenance where 50/125 multimode fiber performances is critical. Achieve seamlessl networking testing and troubleshooting with this temperature resistant loopback device that maintains ≤0.2dB attenuation across -40°C - 80°C operating ranges. Specifications: Size: 22x67x10mm. Weight: 30g. Insertion loss: ≤0.2dB. Return loss: ≥50dB. Operating temperature: -40°C - 80°C. Package Includes: 3pcs Fiber Loopback note: 1.Please allow 1-2cm errors due to manual measurement, make sure that you donot mind befores you order. 2.Due to the differences between different monitors, the picture may not reflect the actual color. Thanks for your understandings.