This black version of POLYTOUR FIRE delivers surgical precision on full swings. The feel is firm but nicely dampened, with a surprisingly low level of shock on off-center hits. Yonex has made this string with its unique Silicone Oil Infused Filament (SIF) Technology. This is a manufacturing process that reduces stringbed friction, enabling the strings to snap back with vicious force (resulting in heavy spin). Although this might be a little too firm for beginners, we think it is perfect for intermediate and advanced players, especially if they want control, durability, and spin. Tension maintenance is above average. 

• Gauge: 16L/1.25mm
• Length: 39ft/12m
• Composition: Co-polyester Monofilament (finished with high polymer polyester)
• Color: Black