TC-3B preamp, a 3-band EQ system for bass guitars.  Three center-click pots for bass, mid and treble controls included, as well as installation manual

Push-Pull Potentiometer (500k), for volume control, including a DPDT switch that can be used for coil tapping, series/parallel selection, etc.
Price: US$ 10.00 (plus shipping costs)

Blend Potentiometer (250k), for pickups selection (panning), with center detent.
Price: US$ 7.50 (plus shipping costs)

Volume potentiometer (500k), for volume control.
Price: US$ 2.50 (plus shipping costs)

Tone potentiometer (500k), for tone control.
Price: US$ 2.50 (plus shipping costs)