US Open Extra Duty SWISS 18x 4-Ball Tennis Packs

The official US Open tennis ball since 1978.

• Approved by USTA and ITF for competition
• Made with premium felt from Tex/Tech Industries
• Extra Duty: Optimal performance and durability on hard courts
• High Altitude: The high-altitude core is ideal for tennis courts at elevations above 3000ft (914.4 m).
• Regular: Optimal performance and durability on clay and indoor courts
• Grass: Optimal performance and playability on grass courts

The tennis ball range at Tennis Factory Bopp in Wallisellen extends from tournament balls to training balls and even children's balls. Buy the right ball for every occasion. We equip entire tennis clubs with tennis balls, and if you also need tennis balls for the next Interclub season, contact us today. Upon request, we will gladly send you our tiered 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 upon request. In addition to tennis balls, Signum Pro produces the most price-performance-strong tennis strings. The most well-known Signum Pro strings are probably the Signum Pro Tornado, Signum Pro Xperience, and the Signum Pro Hyperion. Check out the string reels category at https://tennisfactory.ch/saiten/saitenrollen/ for more.

Official Tournament Balls

All official tournaments, as well as the Rado Interclub and the Rado Club Champion Trophy, may only be played with Swiss Tennis partner balls, the so-called "official balls".

In the U10 and U12 (R7-R9) categories, the also homologated Stage 1 (green) balls are used at competition level. These balls have reduced pressure, are about 25% slower, and bounce less high than conventional yellow balls.

Please note that all official balls (exception: Stage 1 balls) must have a Swiss Tennis logo imprint! Violations will result in sanctions for the tournament organizer.

• Babolat Team (Pressurized ball)
• Babolat Green (Stage 1)
• Head Tour / ATP (Pressurized ball)
• Head T.I.P. green (Stage 1)
• Wilson US Open Swiss Tennis (Pressurized ball)
• Wilson Starter Play (Stage 1)