ChairSlippers are Pre-Cut tennis balls that come in 3 sizes and 5 colors. They are engineered specifically as a chair glide with an extra thick (5mm) reinforced rubber interior and super heavy duty wool blend felt for an attractive, long lasting, tight fitting and economical solution for schools, hospitals, restaurants or churches. They also eliminate the terrible noise from sliding chairs across hard surfaces. Three-year guarantee. ChairSlippers have been protecting floors since 2003. Over 12 million sold!!