Mercury - NMEA2000 6-Way Junction Box Network Distribution Block 84-8M0138268. Overview. Building a clean, reliable NMEA2000 network gets much easier when you use a proper distribution block instead of a string of individual T-connectors. The Mercury 84-8M0138268 NMEA2000 6-Way Junction Box gives you a solid, centralized hub for your backbone, helping reduce clutter, improve durability, and make future expansion far simpler. Designed for any standard NMEA2000 5-pin connector, it supports both ma