Yonex Ti-10:     Ti-10 Long Extra stiff flex rating. Isometric square head shape creates a higher, larger sweet spot. Titanium mesh at 3 and 9 o'clock increases maneuverability. Racquet comes unstrung Avg. Weight Strung String Pattern Stringing Min. Stringing Max. Construction Flex 100g (3.5100g (3.5ozoz) 22x22 16lbs 20lbs Frame: Graphite, Shaft:ultra HM graphite-titanium Extra Stiff         Yonex Isometric Swing Power 900:    Isometric Swing Power 900 Long Regular / Stiff flex rating. Isometric square head shape creates a larger, higher sweet spot. Available in Regular or Stiff flex. Racquet comes unstrung Avg. Weight Strung String Pattern Stringing Min. Stringing Max. Construction Flex Range: 91g (3.2oz) 97g (3.4oz) 22x22 16lbs 20lbs Frame: HM Graphite, Shaft: Ultra HM Graphite Regular/Stiff       Yonex Ti-5:       Ti-5 Stiff flex rating. Isometric square head shape creates a larger, higher sweet spot. Titanium mesh at 3 and 9 o'clock increases maneuverability. Racquet comes unstrung. Avg. Weight Strung String Pattern Stringing Min. Stringing Max. Construction Flex 100g (3.5oz) 22x22 16lbs 20lbs Frame: Graphite/Titanium, Shaft: Graphite Stiff           Yonex isometric 60:   Isometric 60 Light Medium stiff flex rating. Isometric square head shape creates a larger, higher sweet spot. Super lightweight frame for maneuverability.