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
Learn About Surgeon's Cuffs, and Cuff Buttons [photos]
Jacket: Sleeve Buttons | DressedWell
Why are there 4 buttons on suit sleeves? - Quora
Men's Sleeve Buttons | What Are They For?
Jacket Cuff Button Styles – Bond Suits
Sleeve Buttons - Break uniformity without being flashy