NSI stacked neutral assemblies offer the ultimate in compact design and performance. Wire holes are stacked to minimize width. One-piece construction provides superior mechanical performance. It is made from high-strength 6061T-6 aluminum alloy. Include a 350 mcm main lug and a high-strength, glass-filled polyester mounting base for isolated - mounting. Available in 24 wire holes (4-14 awg). UL Recognized and CSA certified.