The phrase "volume dial" typically refers to a control on devices, such as radios or televisions, that allows you to increase or decrease the sound or volume. Full definition
There are no buttons of any sort on the headset itself, although the detachable 6 - foot 3.5 mm cable has a handy in - line volume dial for quick adjustments. (techradar.com)
Yes, I listen to loud music and it sounds good, but I need an actual volume dial not some screen to touch. (edmunds.com)
It has an on - screen volume dial since there are no physical buttons. (the-ebook-reader.com)