ByMary Whitfill Roeloffs,

Forbes Staff.

The world’s top tennis players are battling it out on the court at the US Open, with some sporting high-dollar luxury watches and custom diamond jewelry worth tens of thousands of dollars.

Almost every top tennis player has a contract with one luxury watch brand or another—Rolex sponsors three of the top five women’s players, four of the top five men and the tournament itself—and brands gift some of their flashiest pieces to players to wear on and off the court.

Some players—like Alexander Zverev, Andrey Rublev, Jessica Pegula and Elina Svitolina—wear high-dollar timepieces while playing their matches but a majority of players slip them on after for post-game interviews, press conferences and strategic wrist close-ups.