INNOMAX Genesis 400 Gentle Wave King Waterbed Mattress, King Genesis 400 Gentle Wave Deep Fill King Waterbed Mattress for full depth rigid side box frame Gentle Wave Performance and 20 year warranty Wave Reduction and weightless feel featuring Gentle Wave Performance and gravity neutral fluid suspension mid-body support Multi-Layer wave elimination system and 20 mil premium paralyzed vinyl Body Profile sleep surface generously overcut Low Tension Mattress design 4 Way tethered support system for Integrated Internal Component Stabilization and T-Corner Lap Seam construction Use with approved Waterbed Heater Waterbed Safety Liner Waterbed Water and Vinyl Conditioner Do Not Fill above Safety Liner