The 9252 Semi-Waveless Hardside Waterbed Mattress is for the sleeper who likes some wave but not too much. It’s two full size layers of fiber control cuts the waviness just enough. This model does not have additional lumbar support. The 9252 model has:
•  A full, 9 inch depth for maximum flotation and minimum displacement between sleepers of different size
•  Tethered Wave Control Systems keep the wave control/support system in place and prevent shifting of those materials
•  Main seams are recessed completely underneath the mattress to eliminate flexing and stress on those seams
•  A black bottom panel made from a special vinyl formulation that is better at withstanding heat from the heater
 
The 9252 Semi-Waveless Hardside Waterbed Mattress with Lumbar Support utilizes Sterling’s Premium 18mil Endura3 Bali Blue Vinyl. Endura3 is formulated with the finest resins available and is engineered to be the best material possible, making for a durable, long-lasting, high quality waterbed.