Yonex Power Cushion Fusion Rev 4 Womens Tennis Shoes are equipped with Power Cushion Plus shock-absorbing material, and provide a fit that feels like a perfect union between foot and shoe. The fourth installment of the FUSIONREV series, highly praised for their comfortable fit, is equipped with Yonex’s most effective Power Cushion Plus technology. The shock-absorbing, resistant Power Cushion material, offering spring and reducing fatigue — and which can bounce an egg dropped from a seven-meter height without breaking it — has been refined and further improved to Power Cushion Plus, producing 25% more shock absorbancy, 12% more resistance, and further reducing fatigue and improving sprinting ability. Flexion Upper features a shoelace placement designed to avoid putting pressure on the navicular and cuneiform bones like most shoes tend to do. The Inner Boot Structure with a flexible tongue also snugly wraps the instep, and combines with the Flexion Upper to produce an improved fit, creating a perfect union of foot and shoe. The Inner Boot Structure combines a tongue that snugly wraps the instep from the shoe opening. The foot is wrapped in flexible material from metatarsal to heel, producing a gentler fit. Please note Yonex shoes tend to be small fitting and it is advisable for most to go up by a half or full size.