Features a construction of 100% long stable cotton whose fibers are longer and finer, Sateen woven at 600 thread count per square inch making this water bed sheet set soft yet comfortable. The waterbed fitted sheet is similar to the flat sheet except it has an extra triangular fabrics sewn at the four corners and both flat and fitted are sewn together by the footer so bed stays made. In addition, the fitted sheet is always made few" larger than the water mattress so the extra fabric can cover the mattress sides when made. The Poles attachment feature is an additional feature that is used to keep the triangular fabric fully opened so fitted sheet doesn''t come off easily. If your sheets include the pole attachment feature, you can insert 12" long wooden or plastic pole that is 0.5 inch in thickness (any pole can be used as it''s NOT INCLUDED). That Pole when inserted will keep the triangular fabric fully opened under your water mattress and makes it harder for the fitted sheet to come off. - Royal Tradition- Single Ply Construction- 100-Percent Cotton from long stable yarn- 600 Thread Count per square inch- Authentic Sateen, Solid- Flats and pillowcases made with 4" hemming - Fitted Sheet Pockets Made With POLE Attachment for Better Hold- Deep fitted sheet fits mattresses up to 15" deep and fully elasticized for snug fit- Machine washableAvailable Sizes Include:- Queen: One Queen Flat Sheet 67" wide x 96" long, One Queen Fitted Sheet 60" wide x 84" long & Two Standard Pillowcases 20" wide x 32" long each.- California king: One King Flat Sheet 80" wide x 96" long, One King Fitted Sheet 72" wide x 84" long & Two King Pillowcases 20" wide x 40" long each.Note! Poles are NOT included