Tempur Pro Mattress, Semi-Double, 21cm Thickness, Firm, Made in Denmark

I've used this since May 20th, but I feel it's not firm enough for me, so I've decided to list it.
I always used a waterproof mattress protector. There are no noticeable stains.

Tempur-Pedic Mattress | Tempur-Pro | 21cm Thickness | Firm | Pressure-Relieving Mattress | 10-Year Manufacturer Warranty | Made in Denmark