The Molex 389690003 is a 3-circuit barrier terminal block from the 38969 series, designed for through-hole mounting with PC pin termination. It accepts 8-20 AWG wire and uses screws with a captive plate for top termination — the captive plate keeps the screw retained during field service, a practical detail when you are working in a panel and do not want to lose hardware. Rated 50 A at 600 V, this strip handles the main power feed in industrial control cabinets, power distribution panels, and similar equipment where a UL94 V-0 rated PBT insulator is required.
The 389690003 shares the same 0.500" pitch, 50 A rating, and 3-wall barrier design as the 6-circuit 389690006. If your panel schematic calls for 3 circuits, this is the one; if you need 6, step up to the 389690006 without changing any other specification.