Tennis balls US Open Extra Duty SWISS 4 pieces

The official tennis ball of the US Open since 1978.
Approved for competition by the USTA and ITF
Made from high-quality Tex/Tech Industries felt
Extra Duty: optimum performance and durability on hard courts
High Altitude: The High Altitude core is ideal for tennis courts at altitudes above 3,000 feet (914.4 m).
Regular: optimum performance and durability on clay and indoor courts
Turf: optimum performance and playability on grass courts

The range of tennis balls from Tennis Factory Bopp in Wallisellen extends from tournament balls to training balls and children's balls. Buy the right ball for every occasion. We supply entire tennis clubs with tennis balls, and if you also need tennis balls for the next interclub season, please contact us today. On request, we'll be happy to send you a detailed price list for large quantities of tennis balls. Our balls are available in the brands Wilson, Babolat, HEAD and Signum Pro.
As Signum Pro Switzerland, we are particularly proud of our Signum Pro balls, which we can only send you on request. In addition to tennis balls, Signum Pro produces the best value tennis strings. The best-known Signum Pro strings are Signum Pro Tornado, Signum Pro Xperience and Signum Pro Hyperion. Take a look at the string spools category at https://tennisfactory.ch/saiten/saitenrolle/.
Official tournament balls
All official tournaments, as well as the Rado Interclub and Rado Club Champion Trophy, can only be played with Swiss Tennis partner balls, known as "official balls".
In the U10 and U12 categories (R7-R9), Stage 1 balls (green), which are also approved, are used at competition level. The balls have reduced pressure, are around 25% slower and bounce lower than conventional yellow balls.
Please note that all official balls (with the exception of Stage 1 balls) must bear a printed Swiss Tennis logo! Violations will result in sanctions for the tournament organizer.

Babolat Team (pressure ball)
Babolat Green (Step 1)
Head Tour / ATP (pressure ball)
Chef T.I.P. green (Step 1)
Wilson US Open Swiss Tennis (pressure ball)
Starter set Wilson (Step 1)