I present to you The Knob of Contrast (sounds epic, eh?) which serves the purpose of. This is the latest artwork I did for Samplephonics, called
Dribbble - Gaming Controller Icon by Piotr Kwiatkowski
Dribbble - Volume Knob by Paul Flavius Nechita
everything is energy (process) – light dimmer switch.
A showcase of Simple ios icon design 8 Icons Showcase: 10 Simple iOS Icon Designs
Dribbble - knob 2 by ididi