Designed with stability, comfort, and durability in mind, the Head Revolt Pro 4.5 takes what you loved from the previous versions and makes subtle improvements for a great all-around performer. The upper has been reconstructed for a more supportive and locked in fit. Aesthetically, the upper is more technical and clean looking, with a wave-like design that contours nicely to your feet and also allows for ventilation, with a mesh layer underneath. Within the midsole the Tri-Nrg system not only delivers comfort and shock-absorption, but helps to stabilize your feet when pushing off and accelerating. Head's signature Hybrasion+ rubber has been formulated to withstand the wear and tear while playing on hard courts, but the traction will perform on a variety of court  surfaces. Outsole is backed by a six-month outsole durability guarantee.