Handcrafted to be the only mattress you'll ever need to own. The Powercore® 3 spring unit comes with a lifetime guarantee. Natural latex, certi-purUS gel foam and nano spring comfort cassettte options are plush yet supportive and deeply comfortable. Lifetime features, warranty and added benefits in this next generation of our famous Powercore® Lifetime mattresses.The reversible/replaceable comfort cassettes offer softer/firmer options depending on which side of the cassette faces up so you can fine tune the feel (king uses two comfort layer cassettes that can be reversed for firmer or plusher feel on left and right sides of the bed).Lifetime 8 (Luxury Firm) - Best for back + stomach sleepers, the Lifetime 8 has a comfort cassette that can be flipped for a firmer or softer feel. The King size has 2 cassettes that can be flipped independently, ideal for couples with different comfort preferences. (Recommended by Consumer Reports)  Lifetime 9 (Luxury Plush) - The Lifetime 9 upgrades the Lifetime 8 with a layer of nano springs that add a soft feel. You’ll feel like you’re suspended in a cloud with cushion support that’s not too firm + not too soft. Lifetime 10 (Ultra Plush) - Best for side sleepers + those that love a softer mattress. One of the most luxurious options Rogers has to offer. The comfort cassette can be medium or extra soft, cradling you in cushion. Solid back support underneath to keep you in alignment. Additional layers of cradling certi-pur gel foam and nano springs offer the most luxurious sleep surface possible.  NEW Safety-Sealed packaging is hermetically machine sealed at our factory before shipment.