Wire gauge and tab width match
The 3-520404-2 is the 0.187" tab-width member of TE's Ultra-Fast Plus fully insulated female quick-disconnect receptacle line, accepting 14-16 AWG wire. Tin-plated brass contact, 0.032" tab thickness, free-hanging crimp termination — the insulation diameter range is 0.090" to 0.160".
Tab width variants in the series
Within the Ultra-Fast Plus 14-16 AWG family, the 3-520404-2 (0.187" tab) sits alongside the 3-520406-2 (0.250" tab, same 0.032" thickness) and the 3-520402-2 (0.187" tab, 0.020" thickness) — the wire gauge, insulation diameter, and overall length are shared across the three.
