PRE-CUT: Those tennis Balls are precut to be ready to be installed PROTECTORS: Precut Tennis Balls can protect floor and carpets with soft felt exterior PRE-CUT OPENING for safety and convenience Applied Surface: Tile, Concrete and Hardwood Floors MULTI-USE: Heavy Duty Thickness/Chairs, Desks, Stools, Tables, Walkers These pre-cut tennis balls are suitable for most walkers and it is very easy and safe to install our pre-cut tennis balls