The blood circulation is felt more intensive with the roller
"This product is of high quality and served us for around 30 times before my husband felt that the needls were not sharp enough, as in the beginning. He notes that blod circulation was felt somewhat higher in the areas where the roller was applied. He also applied minoxidil some time after the application of the roller, and the result was somewhat better. He recommends buying two or three rollers at once so that you save on delivery after the first one is not felt sharp enough. Overall he recommends this product"