After a long search in Amazon, I chose this fan model. The device was already assembled and I could take it into operation promptly. There is a fan, which has a diameter of 30 cm and is 3-stage adjustable. The background noise is kept within limits and at level 1 I was still asleep. With a light sleep stage 3 is probably not very suitable. The fan moves at a 90 degree radius. Processing met my expectation.
