BoxTop Waterbed with Memory Foam Durable and Long-lasting. Only high gauge, top grade virgin vinyl material is used in the construction of this tube waterbed. Furthermore, all corner seams - the points of greatest pressure - are reinforced. 85% Motionless / Waveless. This waterbed features our F4 Waterbladder. Four super-thick fibre layers work together to effectively minimize the motion in the bladder. Adjustable Firmness. The firmess or softness of the bed can be better customized by filling the bladder with more or less liquid. Memory Foam PillowTop: Relieves Back Pain. This waterbed features a thick and plush "Box" pillowtop that contains the pressure-relieving Memory Foam. This revolutionary foam - originally formulated by NASA - reduces pressure points and conforms to the shape of your body: Great for anyone who's ever suffered from back or hip pain. Superior Edge Support. 1.8 lbs density sloped wall foam rails maximize side support against the pressure of the water bladder, preventing the bed from bowing out. In addition, high strength stitch bond fabric connecting the rails holds the bed components firmly together from head to toe. Superior Base Support. This waterbed sits on an 8" Waterfall Foundation that is especially reinforced and designed for the Savannah. Premium Split foundations are stadard on all Queen and King beds .