For several weeks this pillow now have acquired.
What inspired me in this pillow the possibility of adjusting the hardness of water. When unpacking, I had felt the pillow as thick. After filling with water (2 liters) I tried it and was pleasantly surprised at how soft it is.
Immediately after the first night, I could feel the neck pain disappeared slowly but steadily.
I personally recommend the purchase of any person who wishes to adjust the firmness of his cushion individually or struggling with neck and back pain.