THE MOST COMFORTABLE SEAT IN THE HOUSE. Miracle Bamboo® Cushion promotes proper seated posture and turns any seat into the most comfortable seat… at home, work, sporting events, even in your car! Portable seat cushion is made of high density orthopedic foam that won’t flatten out. Viscose-from-bamboo cloth cover remains cool. A cutaway in the back eases pressure on the tailbone. Poly/viscose cover is removable for machine washing. 17.5”Wx2.75”Hx14”L.