Spandex Chair Cover
This is the real thing, real knit spandex, not polyester imitation.  
Stretches 4 ways, flexible on the size.   Fabric has about a 66% stretch ability, which means a chair back of 15" wide stretches to a 25", so the types of chairs this can fit can range broadly.  
Wrinkle FREE, Stain resistant.
Sizing:
chair back: 15" wide x  17" tall
Seat area:  15" x 16"
Legs: 15' tall