Bed-in-a-Bag King Waterbed - Down Alternative Mattress Pad/Topper-Fully Reversible (Double Life)-1" w/Stay Tight Anchor Straps Fully Reversible. Hypoallergenic. Unbeatable Factory Direct Price. 95gsm Super Soft - Durable - Microfiber Cover Material. Dimensions: King Waterbed Mattress Pad: 72" x 84". Thick - Down Alternative fill. Machine Washable.