String comparison
Pro Line II vs Poly Tour Pro
Kirschbaum Pro Line II against Yonex Poly Tour Pro: ratings, specs and which one fits your junior.
The short answer
Both are polyester strings. Pro Line II leads on power, durability and tension hold. Poly Tour Pro leads on control and comfort. For a junior with arm concerns, Poly Tour Pro is the safer choice. Pro Line II costs less per set.
Ratings
Power
Spin
Control
Comfort
Durability
Tension hold
Ratings are on a 1–10 scale. The higher score is in bold when they differ.
Pick Pro Line II if…
- You want more power (7 vs 6 out of 10)
- You want more durability (8 vs 7 out of 10)
- You want more tension hold (8 vs 7 out of 10)
- Your player is younger (recommended from age 12 vs 13)
- You want to spend less (from $10 vs $14 a set)
- Best for: players wanting soft, responsive poly
- Best for: all-court players seeking versatility
- Best for: those who want poly control with better feel
Pick Poly Tour Pro if…
- You want more control (9 vs 8 out of 10)
- You want more comfort (7 vs 6 out of 10)
- Arm comfort comes first (arm friendliness 4/5 vs 3/5)
- Best for: power players wanting control
- Best for: players seeking soft poly with precision
- Best for: those who like dead, muted feel
Specs side by side
| Spec | Pro Line II | Poly Tour Pro |
|---|---|---|
| Type | Polyester | Polyester |
| Construction | Round co-polyester monofilament with pre-stretch treatment | Round co-polyester monofilament with high-temperature stretching process |
| Gauges | 16, 17, 18 | 16L, 16, 17 |
| Stiffness | Medium | Medium |
| Set price | $10–13 | $14–18 |
| Reel price | $90–110 | $150–180 |
| Arm friendliness | 3/5 · Moderate | 4/5 · Good |
| Cost to maintain | 5/5 | 4/5 |
| Recommended from | Age 12 | Age 13 |
| Levels | Intermediate, Advanced, Elite | Intermediate, Advanced, Elite |
| Play styles | Baseliner, All court, Big hitter | Baseliner, All court, Big hitter |
| Junior tension | 50-54 lbs for juniors. Pre-stretched for better tension maintenance. | 50-54 lbs for juniors. Yellow version plays slightly softer than black. |
Pro Line II in short
Kirschbaum Pro Line II is one of the softest and most responsive co-polyester strings available. Built on 20+ years of German polyester expertise from the company that pioneered polyester tennis strings, Pro Line II offers better pocketing and a more forgiving feel on off-center impacts compared to traditional polyesters. The pre-stretch treatment ensures consistent playability with precise and predictable response, enabling players to swing bigger when going for pace and spin.
Poly Tour Pro in short
Yonex Poly Tour Pro is a softer playing poly stretched at high temperature during production to improve tension maintenance. "I felt like I could put the ball on a dime with it!" - exceptional control on fast swings. The ball seems to sink into it like a pillow at contact. Despite being firm, it has above average comfort for a poly with the yellow version playing slightly softer than black. Not the most spin-friendly in the Yonex family (actually the least), but the control and predictable response make it a favorite among power players. Don't try to get more than a month out of it - when it dies, it's done.
Pro Line II vs Poly Tour Pro: quick answers
Which has more spin, Pro Line II or Poly Tour Pro?
They tie on our spin rating (7/10 each).
Which is more arm-friendly for a junior?
Yonex Poly Tour Pro scores 4/5 for arm friendliness, against 3/5 for Pro Line II. It is recommended from age 13.
Which lasts longer?
Kirschbaum Pro Line II rates 8/10 for durability against 7/10.
Which is cheaper?
Pro Line II costs about $10–13 a set and Poly Tour Pro about $14–18, at typical retail.
The short answer and the "pick if" lists are generated from our ratings and junior data only. Data verified 2025-01 (Pro Line II) and 2025-01 (Poly Tour Pro).