A "next" icon represented by an arrow inside an oval button.

Next Icon

An oval on and off button switch or symbol.

Oval On And Off Slider

An oval on and off button switch or slider.

Two oval on and off button switches in opposite directions.

Three vertical slider bars with oval buttons in different positions.

A video button icon or play button inside an oval.

Handheld flashlight with on/off button seen from the side.  

A video button icon or play button inside an oval with shadows.