Updated for 2011, the Head Youtek IG Speed MP 18x20 is the new racquet used by Novak Djokovic and has a denser string pattern for improved control and stringbed stiffness in the IG Speed range of frames. Slightly wider 21mm beam, 100 square inch head, standard 27 inch length for a more forgiving feel than many of Head"s other players frames, but without sacrificing control and feel. Introduces the use of lightweight Innegra fiber which in conjunction with Head carbon composite improves shock absorption and stability. Continues the use of d3o and DuPont Teflon grommets as found in the previous generation Speed MP. This combination of specifications adds up to a nicely controlled frame for advanced players with established strokes.Head continues d3o technology in the Head YouTek line, and is a "smart" material in that it behaves differently under varying dynamic loading or impact. Integrated in the frame lay-up and positioned in the shaft area (where the racquet flexes the most), d3o seeks to help players maximize performance on all shots. High speed impacts lock d3o together within nanoseconds at the molecular level, stiffening the frame to provide maximum power. Conversely, on slower speed impacts, the d3o molecules absorb the impact providing softer touch for better feel.The IG Speed MP also uses a DuPont Teflon grommet system that reduces friction. Less friction means maintaining more of the strings energy, and a resulting slight increase in power.Headsize:100 sq. in.Length:27.00 in.Weight (strung):11.60 oz.Stiffness (Babolat RDC):65Balance:12.90 in. Head LightCross Section:21mm Straight BeamSwingweight:315 kg*sq. cmString Pattern:18x20Grip:Head Hydrosorb