Power Your Fiber Optic Network Testing with Precision & Endurance Keep your critical certification and troubleshooting missions running longer. This 01WQ0037-05 replacement battery is the intelligent power source engineered for EXFO FTB series Optical Time Domain Reflectometers (OTDRs) like the FTB-2 and FTB-500. Featuring a SMBus communication port for accurate system monitoring and built with high-quality NCR18650GA cells, it delivers a reliable 95.04Wh (6600mAh) at 14.4V for extended field operation.