BETA Polymer Technology provides maximum dynamic stiffness and repulsionZyWeaVeTM core prevents tension loss and maximizes strength and durabilityZyMax 69 Fire: Ultimate StrengthUsage:Professional and amateur playersFor optimum repulsion, power and shot makingFor minimum tension loss and maximum strength and durabilityStringing tension:up to 40 lbs (18 kgs)Cut length 10m set, no retail packaging