What the 387800102 is
The Molex 387800102 is the 2-circuit member of the Beau 38780 dual-wall barrier terminal strip series. With a 0.438" (11.12 mm) pitch, it is rated 15 A per circuit at 300 V and accepts 14–22 AWG wire. The top termination is screw-clamp; the bottom is closed. The housing is black thermoplastic with UL94 V-0 flammability, zinc clear-chromate terminal screws on steel, and the assembly carries a flange for chassis or panel mounting.
What the ratings mean for your panel
The 0.438" (11.12 mm) pitch is the controlling dimension for panel cutout and mounting hole spacing. The 300 V rating places this in low-to-medium-voltage panel wiring — the 15 A per circuit is the more restrictive limit when both ratings are approached simultaneously.