The Molex 0391002012 is a 12-circuit enclosed barrier terminal strip from the Eurostyle 39100 series, designed for panel-mount power distribution where each circuit handles 30 A at 600 V. The 0.394" (10.00 mm) pitch gives the creepage distance needed for that voltage rating without crowding the wiring trough. It accepts 10-18 AWG wire — 10 AWG is the practical size for a 30 A circuit, so the terminal screw and clamp are sized accordingly.
Dual-row layout — 12 circuits, 24 wire entries
Each of the 12 circuits has two screw terminals (top termination, closed bottom), for a total of 24 wire entries. That lets you land an incoming feed and an outgoing load on the same pole, or use one side as a daisy-chain jumper point. The dual-row arrangement keeps the terminal strip compact on the panel — 12 circuits in a single row would be nearly twice as long.
The 0391002013 is the 10-circuit sibling in the same Eurostyle 39100 series, same 0.394" (10.00 mm) pitch, same 30 A / 600 V rating, same dual-row screw termination.