Most cars sold after 1919 were equipped with an electric starter, which was engaged by a small round foot-operated button switch on the floor.

For example, a pigeon may be required to peck a button switch ten times before food appears.

Medium head only with push button switch.

It can be used in situ or pulled out for rinsing, and a button switches between gentle and strong flows.

Alternatively, on some keyboards, pressing the (literally no conversion) button switches between katakana and hiragana.