The JBX01087 400GBASE-VR4 QSFP-DD transceiver represents the cutting edge of optical networking technology, specifically engineered for organizations requiring ultra-high-speed data transmission. This module is a direct replacement for Cisco's QDD-400G-VR4-S, offering seamless integration into existing infrastructure without compatibility concerns. **Key Technical Specifications:** This transceiver operates at 400 gigabits per second over multimode fiber, utilizing an 850nm wavelength that maximizes transmission efficiency in short-reach applications. The 50-meter transmission distance over OM4 multimode fiber makes it ideal for intra-data center connectivity and high-density campus networks. The QSFP-DD form factor provides superior density compared to older transceiver types, allowing deployment of more connections in limited physical space. **Connector and Fiber Compatibility:** Equipped with MTP/MPO connectors, the JBX01087 facilitates rapid deployment and reconfiguration. OM4 multimode fiber support ensures compatibility with modern data center fiber infrastructure while maintaining cost-effectiveness compared to single-mode alternatives for short distances. **Standards Compliance and Safety:** Fully qualified to IEEE 802.3bs specifications and CMIS standards, this module guarantees interoperability with standards-compliant equipment. Comprehensive safety certifications including Class 1 Laser classification, TUV, UL, and FDA compliance (21CFR 1040.10) ensure workplace safety and regulatory adherence. **Build Quality and Reliability:** Constructed with premium metal casing and precision laser transmission technology, the transceiver delivers robust performance across a wide operating temperature range (0-70°C). RoHS and ELV compliance demonstrates environmental responsibility without compromising performance. **Support and Service:** Included 90-day limited warranty provides peace of mind. Custom brand programming is available for organizations requiring OEM specification compliance. Free standard shipping on orders exceeding $99 enhances value delivery.