Refreshing Tencel Lyocell Luxury Bed Sheets: Split Head, Split Top, Split Head Flex Style Bed Sheets. We carry Split Head Queen, Split Head King & Split Head Cal King Sizes. These sheets are designed for your flex top/head adjustable mattress sleep system where the top of the mattress is split. Designed for all flex style systems. Treat yourself to a state of ultimate comfort and top your high end mattress with a set of our Refreshing Tencel Lyocell Luxury Specialty Bed Sheets.