These Official 12" K-Master fastpitch softballs have .47 C.O.R. and 375 lbs compression with white stitching and covers. These Worth's ISC softballs have a high density Poly-X cork and SYCO composite leather cover for added durability. •ISC •12 inch •.47 COR •375 Compression •High Density Cork Core •Syco Cover •White