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sirius
For an unbeatable experience and top-level performance.
String Project Sirius is a monofilament tennis string that promises top level performance and an exceptional playing experience.
It has been developed using state-of-the-art materials and advanced manufacturing processes to ensure maximum performance.
String Project Sirius
String Project Sirius
String Project Sirius

On-court performance
The Sirius string is highly versatile and adapts to different playing styles. On court, it offers an unprecedented combination of spin, power and control. Moreover, thanks to its ‘Arm Friendly’ technology, it is designed to offer a high level of comfort during play.
Another strong point of Sirius is its exceptional durability in tension maintenance. This means it will maintain its playing characteristics for a long period of time, offering consistent performance over time. Regardless of the player’s needs, this string is able to meet them.
Sirius is a tennis string that combines high level performance with comfort, durability and versatility, offering an unparalleled playing experience on the court.
Characteristics
Section
Circular
Calibers
1,25 (16L) | 1,30 (16)
Parameters detected in lab through tests performed by Pro-t-one property of engineer G. Medri.
Lab Test
Dynamic Stiffness
225 g/mm
Stress Range
17 / 23 Kg
Download the PDFs of the laboratory tests:
Production Processes
Pre-Stretch
Thanks to the pre-stretch of the core, the entire string minimizes the loss of strain and, at the same time, it allows to reduce the stringing tension.
Multiple Heating
“Heating treatments” remove internal stress and align string’s potential irregularities. Moreover, they make strings more flexible and elastic.
Liquid Wax
The string is perfected with a wax layer. This treatment extends the duration substantially reducing the wear and making stringing easier.
Low Friction
String’s Friction’s decrease offers: diminished strings’ motion, greater potential spin due to greater snap back and a lasting duration.
Spring Load
This technology allows molecules’ chains to twitch several times resulting a loss of minimal tension and, above all, keeping a higher feature’s steadiness.
Prices
1 stringing
Single Set
€ 12,90
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
3 stringings
3 Sets Pack
€ 38,70
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
6 stringings
6 Sets Pack
€ 77,40
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
About 17 stringings
200 meters Bundle
€ 149,00
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
Expert’s Reviews
Blogs

Tennis Nerd
tennisnerd.net
This was a very enjoyable string to string. The wax coating and round profile help the string move easily through fingers and grommets. My first hit was in a Wilson Blade 98 V8 18/20. The string felt soft to me (like most String Project strings) and I wanted to maintain control, so I went for 53 lbs or 24 kg.
sirius
For an unbeatable experience and top-level performance.
String Project Sirius is a monofilament tennis string that promises top level performance and an exceptional playing experience.
It has been developed using state-of-the-art materials and advanced manufacturing processes to ensure maximum performance.

On-court performance
The Sirius string is highly versatile and adapts to different playing styles. On court, it offers an unprecedented combination of spin, power and control. Moreover, thanks to its ‘Arm Friendly’ technology, it is designed to offer a high level of comfort during play.
Another strong point of Sirius is its exceptional durability in tension maintenance. This means it will maintain its playing characteristics for a long period of time, offering consistent performance over time. Regardless of the player’s needs, this string is able to meet them.
Sirius is a tennis string that combines high level performance with comfort, durability and versatility, offering an unparalleled playing experience on the court.
Characteristics and Lab Test
Parameters detected in lab through tests performed by Pro-t-one property of engineer G. Medri.
Section
Circular
Calibers
1,25 (16L) | 1,30 (16)
Dynamic Stiffness
225 g/mm
Stress Range
17 / 23 Kg
Download the PDFs of the laboratory tests:
Production Processes
Pre-Stretch
Pre-Stretch
Thanks to the pre-stretch of the core, the entire string minimizes the loss of strain and, at the same time, it allows to reduce the stringing tension.
Multiple Heating
Multiple Heating
“Heating treatments” remove internal stress and align string’s potential irregularities. Moreover, they make strings more flexible and elastic.
Liquid Wax
Liquid Wax
The string is perfected with a wax layer. This treatment extends the duration substantially reducing the wear and making stringing easier.
Low Friction
Low Friction
String’s Friction’s decrease offers: diminished strings’ motion, greater potential spin due to greater snap back and a lasting duration.
Spring Load
Spring Load
This technology allows molecules’ chains to twitch several times resulting a loss of minimal tension and, above all, keeping a higher feature’s steadiness.
Prices
1 stringing
Single Set
€ 12,90
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
3 stringings
3 Sets Pack
€ 38,70
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
6 stringings
6 Sets Pack
€ 77,40
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
About 17 stringings
200 meters Bundle
€ 149,00
*choose caliber later
Free shipping
1 anti-vibration item
2X Overgrip Dry Pack
Expert’s Reviews
Blogs

Tennis Nerd
tennisnerd.net
This was a very enjoyable string to string. The wax coating and round profile help the string move easily through fingers and grommets. My first hit was in a Wilson Blade 98 V8 18/20. The string felt soft to me (like most String Project strings) and I wanted to maintain control, so I went for 53 lbs or 24 kg.