Note: 90x190 ultrathin is a very thin mattress protector Purchase Notice: (all mattresses in our store are like this) Due to the large size of the mattress, our mattress is vacuum packed, so there will be creases or slight deformation when you receive the goods, and the thickness will be less temporarily.2 ~ 3CM does not affect your later use, and will gradually recover after 2~3 days. 1. Due to the sealed packaging of the new mattress, there will be the taste of raw materials after opening the package, which is a normal phenomenon and harmless to human body. It will disappear naturally after ventilation for a few days. 2. The correct measurement method about the size of the mattress: pave the mattress (please be sure to pave the measurement) and measure the size along the middle line to obtain the correct size. 3. It is normal to have an error of about 3cm in length and width. If you cut the edge at hand binding, the size will inevitably vary. If you mind, don't shoot it to avoid unnecessary misunderstanding.