The RS-KDC4-L20-Y is a yellow illuminated On-Off DPST 20 ampere 125 volt rocker switch, 4 pins.
The RS-KDC4-L20-BL is a blue illuminated On-Off DPST 20 ampere 125 volt rocker switch, 4 pins.
The RS-KDC4-20-BK is a black DPST On-Off 20 ampere 125 volt rocker switch, 4 pins.
The MOT-JK42HS40-1704 is a 42mm Nema-17 2-Phase 4-Wire Stepper Motor with 1.8° step angle, 1500 RPM, 12~24V used on CNC machines and 3D printers.