Though this flea collar is cheap, it doesn't do anything against fleas. For the period that I used this product, the number of fleas actually rose on my cat. Granted there may be a different reason for the increase of fleas, the fleas were generally located on my cat's head, right by the collar. In fact, many of them were right behind his ears, and he would actually scratch around the collar where the fleas were biting him. Also, there is a lot of white dust on the collar when you get it. Some of the dust fell onto my cat's coat around his front legs - so watch out for this and make sure to get the dust off of them before they clean themselves.