The RL-PA1A-5V is a single inline 5 volt SPST 5 ampere PC Mount relay.
The RL-PA1A-12V is a single inline 12 volt SPST 5 ampere PC Mount relay.
The RL-PA1A-24V is a single inline 24 volt SPST 5 ampere PC Mount relay.
The RL-APAN3105 is a single inline 5 volt SPST 5 ampere PC Mount relay.
The RL-APAN3112 is a single inline 12 volt SPST 5 ampere PC Mount relay.
The RL-APAN3124 is a single inline 24 volt SPST 5 ampere PC Mount relay.
The (EVU-F2AF30B14) is an adjustable potentiometer THAT can open up many interesting user interfaces. Turn the pot and the resistance changes. Connect VCC to an outer pin, GND to the other, and the center pin will have a voltage that varies from 0 to VCC depending on the rotation of the pot.