The Helix Dusk is a hybrid mattress with a medium sleep feel. It's the cheapest and most basic of the brand's three Dusk models, and all three are designed especially for back or stomach sleepers.
The 11.5" tall, hybrid mattress is handmade in the USA, and includes a layer of springy foam (called a 'latex alternative'), other foams and a layer of coils. At full price it's an upper mid-range model, but there's almost always a discount that'll take it down into the mid-range bracket.
