The Detail Of T-99S New High Quality Multi-fit Flat Wiper Blade Functional Boneless Windshield Wipers One piece spring structure with iron legs Right hand driving and Left hand driving for choice. aerodynamic design, anti-lift in high speed. Durable TPR material. Refill material: natural rubber with special formula, without noise. Passed 72hours salt spray test, anti-aging test, high temperature and low temperature resistance test.