USB Volume Knob : 9 Steps (with Pictures) - Instructables
Griffin PowerMate Multimedia Control Knob for USB Computers, Space Grey - Assignable USB multimedia controller : Amazon.co.uk: Computers & Accessories
USB Volume Control Knob, COOIDEA Volume Controller, Multimedia Controll Knob with one Key Mute/Pause Function for PC, Support Windows/Mac/IOS/Android/Linux (Black) : Amazon.co.uk: Computers & Accessories
Yocto-Knob - Tiny USB interface for reading buttons or potentiometers
Programmable USB Knob | workshop
USB Knob Box Doubles as a Blackmagic Designs Camera Remote | Photons, Electrons, and Dirt
A Classy USB Knob For The Discerning Computerist | Hackaday
USB Volume Control Knob Audio Adjuster with 4.9ft USB Cable PC Speakers Switch Control Module PC Speaker Computer Audio Control|Sound Cards| - AliExpress
One Button, One Knob, USB: Crazy-Simple DIY Teensy Project (And Some Music) - CDM Create Digital Music
AIMOS USB Audio Volume Controller Knob, Volume Adjuster Rotary Computer Speaker Volume Control Switch For Win7/8/10/XP/Mac/Vista Android (Black) | Walmart Canada
Mini USB Volume Control Knob Audio Adjuster with 4.9ft USB Cable PC Speakers Switch Control Module PC Speaker Computer Audio Multimedia Controller Digital Remote Control | Pricepulse
AIMOS USB volume controller, volume control knob, computer speaker volume control switch for PC Win7/8/
AIMOS USB Audio Volume Controller Knob, Volume Adjuster Rotary Computer Speaker Volume Control Switch For Win7/8/10/XP/Mac/Vista Android (Black)
A PIC USB Volume and Mute Knob for Your Computer - Hackster.io