This is a 1 Waveless Tube sold as a replacement for a Tube Bed. It has convoluted foam inside to reduce motion. It does not have specific lumbar support but just the foam at all the same height. It will fit a standard QN or KG size tube bed. With all tubes it is best to fill them to the firmness you would like and add one tube tablet. We sell the tablets too.
Boyd Flotation foam filled waterbed tubes fit inside a 4″ shallow fill softside waterbed mattress. A foam filled tube allows reduces motion while allowing you to independently adjust the level of support, from plush to firm, of each side of the bed.