Flex Top Split California king Mattress Owner? Our 600 Thread count Top Split California King Sheets are finally here! Enjoy the luxury and high quality of our 100-Percent Combed Cotton sheets made for your Adjustable Split Top Flex Top California King Bed. Our Split Top fitted sheet will fit your adjustable mattress perfectly, their Fitted sheets are Fully Elasticized and made with 6 corner pockets to fit up to 18 inches deep mattresses. Fabric Wings (extra fabric) in the middle to cover mattress inner Splits so each side can move freely. Material: 100-Percent Long Staple Cotton Thread Counts: 600 Thread Count Double elastic on each corner for better support Fitted provides snug fit and won't pop-off Deep Pockets to fit up to 18 inch mattress Split Top California sheet set includes: One Flat Sheet measures 110 inches wide X 102 inches long, One Calking Fitted Sheet 72 inches wide X 84 inches long (Splitted at top) pockets to fit 18 inches deep pocket mattress & Two King Pillowcases measures 20 inches wide X 40 inches long each.