The Firmest mattress we have and it's reversible so you can use both sides of the mattress. Reversible mattresses last longer because you're using both sides of the mattress equally. This is for those who want a hard mattress. All the pocket coils are "Offset" (like a honeycomb) and the pocket coils are layered with a 3.0lbs High resolution foam with an ILD of 40. The gage of the coils are 13.5 which is thicker than usual. Thicker coils means a harder mattress. The mattress is finished with a bamboo breathable fabric quilted with a firm 2.0llbs density foam. The surface of this mattress is also firm.