noun
functioning cuff buttons; working buttonholes on jacket sleeves
Refers to jacket cuffs where the buttons can actually be buttoned and unbuttoned, as opposed to decorative non-functioning buttons. Often a sign of higher-quality tailoring.
See also: 本切羽
このジャケットは本開きなので、袖口のボタンを外せる。
This jacket has functioning cuff buttons, so you can unbutton the sleeve cuffs.
noun
surgeon's cuffs
A specific style of functioning cuff where the sleeve can be opened wide, originally designed for surgeons to roll up their sleeves without removing the jacket. A subset of 本開き.
外科医のスーツには、よく本開きの袖が採用されている。
Surgeons' suits often feature surgeon's cuffs.