Knob

A rotary control for continuous or stepped values where space is square. Its knurl and pointer turn; its light does not.

Drag up or right, scroll while it is focused, or use the arrow keys. Hold Shift for fine work.

• It is a role="slider" with aria-valuemin, aria-valuemax, aria-valuenow and a aria-valuetext that includes the unit.
• Reached with Tab; every value is reachable from the keyboard, so dragging is never required.
• The wheel only turns it while it has focus, so scrolling the page never changes a setting by accident.
• Show the value in an <output> under the label; do not rely on the pointer’s angle alone.