R13 Number Bed The Rl3 number bed mattress allows you the ability to adjust your level of comfort and it also provides rejuvenation benefits to help revive your body through out the night. The Rl3 model is made up of a copper infused EnergexTM comfort layer, an air flow comfort layer and a support layer. The cover is an ultra-stretch, temperature neutralizing, smooth top panel. Also includes our new, poly blend, ultra-flex air chambers.