I broke off the lid on one in the third picture so you could see what is inside.
DC 12V/24V to 6V 10A 15A 20A 40A Step Down Converter Regulator 6 Volt Buck Power
???????? TM1637 4 or 6 Digit 0.36" Red 0.56" White Blue 7 segment LED Display Module
7-Segment LED Display 0.36" 0.56" inch TM1637 6-digit
5 of 6A10 Diodes, 6 Amp, 1000 Volt,
Asrock K7S41GX rev. 1.03 Socket 462 Motherboard with AGP 8x