The finished product is of good quality and has a smooth side and one side with knobs that are massaging the buttocks while sitting easily. The pillow promotes flexibility in the lumbar spine area, because you have to compensate for the movement while sitting. This leads me zm degradation unilateral tense posture and helps to carry out the work in a sitting posture. I am satisfied, especially as the pillow has (yet) lost no air. Otherwise, they can be refilled with a small valve.