Tailors of Distinction - Whether they are are functional or not, a suit jacket will have buttons on the sleeve. A suit jacket with sleeve buttons that come undone (surgeons cuffs) is
Why are there buttons on suit jacket sleeves? Here's what they are for
Buttonholes】Functional Jacket Sleeve Buttonholes
What Is the Function of Button Cuffs on a Suit Jacket? : Men's Suits - YouTube