This is an original vintage Knoll seat pad for a Bertoia diamond chair. Made of caramel colored vinyl and split down the middle to allow it to conform to the contour of the chair. Measures 15 inches top to bottom and 17 inches across at the widest point. Has a strap underneath that snaps to attach it to the wire of the chair. Pad is comfortable even though no longer pliable. Good vintage condition with minor signs of use; the strap has lost its elasticity and shows some wear but is still operational.