California King flat top sheet is not properly sized as there is no allowance to tuck into the bottom unless the top sheet is several feet from coming close to the top of the bed so your choice is coverage of the shoulders or feet not both like a correctly sized sheet.  I have two sets, 2 colors both flat top sheet is too short for California king for proper coverage.  Other than sizing, I like this sheet.  I have several other sets in a variety of colors that properly fit those beds.