2PIN Shallow-Depth Back-Rising Terminal Configuration, 1 Normally Open Early-Make (1 NO-EM) Contact Block Attachment, Class 800T Series, Heavy-Duty Silver-Alloy Contact Tracks, -40°C to +55°C Industrial Operational Window | Precision sequence-timing pilot circuit switch block manufactured by Allen-Bradley engineered with advanced geometric mechanical slide contact paths, designed to execute rapid early contact connection logic profiles safely before primary main contact paths shift state across multi-tier relay interlocking grids | Industry Exact Equivalents: Allen-Bradley 800T-XD4, Rockwell Automation 800T-XD4, A-B 800T-XD4 Contact Block | Industry Functional Cross-References: Square D 9001KA3, General Electric CR104PXE, Siemens 3SB3400-0D | Military Specification National Stock Number (NSN): 5930-01-224-8175