Play aggressive first-strike tennis with Laserfibre JB Tour 100 Tennis String in Silver In collaboration with American tennis stalwart James Blake, Laserfibre has produced their 2nd Made in the USA co-polyester string. JB Tour 100 offers a unique feel which was developed and play-tested with James to compete with the top co-polyesters on the market today.The quick bonding titanium dioxide co-polymer formula strengthens and enhances the strings performance with a proprietary additive that increases snap back, ball pocketing and feel. The end product is a blend of power and control to benefit players who can produce substantial racquet head speed. Players familiar with Laserfibres Native Tour, will find JB Tour 100 to be slightly firmer and more control oriented. JB Tour 100 Tennis String is available in 16g (1.30mm) and 17g (1.25mm) in a Silver color.