This Panel Mount Right Angle 10K Linear Potentiometer w/ On-Off Switch is a two-in-one, with both a breadboard-friendly potentiometer and a switch. For the potentiometer-half, you've got a standard linear taper 10K ohm potentiometer, with a grippy shaft. It's smooth and easy to turn, but not so loose that it will shift on its own. It also comes equipped with an on/off switch at the beginning of the shaft's rotation. We like this one because the right-angle legs are 0.2" apart with pin-points, so you can plug it into a breadboard or perfboard. To use the switch, you'll need to solder to the two tabs in the back.
Once you're done prototyping, you can drill a hole into your project box and mount the potentiometer using the included washer and hex nut. We've got plenty of matching T18-splined knobs that you can pair up