Queen Waterbed Sem Wave mattress with zipper cover, Heater & Liner Vinyl Made in USA and Imported Waterbed mattress kit is for a queen size hardside water beds Queen Waterbed mattress kit includes organic cotton zipper cover, semi wave mattress, liner & heater Queen Semi wave mattress and cover make for a very comfortable combination. The semi wave mattress has movement just like the original semi waveless waterbeds Cover unzips off completely from the bottom half for easy maintenance.