Some people like the firm mattress because they think the hard mattress will bring a good protection and support for their body but the mattress material are the foam and as we know this the soft material so how to up the hardness for mattress.

1.Upgraded the wire thickness of spring.

2.Add the spring array not mattress according to the length and the width.

3.Use the good foam to support.

4.Add the brown cotton or coconut(most of it can not compress).

5.Add foam in side can make the side get stronger and avoid to touch the spring unit.