This cat collar is prepared with purely organic materials - and yet it is the first and by many (and very expensive, chemical, recommended by the helpless veterinarian) the only one our outdoor cat - cat (and therefore us) helps! Had our 10th year old Rottiger with increasing age more and more problems "with the skin", that he had to, especially in the head / ear area, constantly scratching. On display were small red puncture, the itchy area of poor cat lost hair un the puncture / scratch wounds crusted .. Since we still have a cat and two dogs, who were all in this respect absolutely free of pain and remained, I could think of Disagree 3 different vets, it probably IN QUESTION by fleas! After I've googled everything lent the topic, mites seemed to me most likely. (The theory of all 3 vets rejected, for whatever reason) I think today, it is simply a grass mite allergy - from December to February was the necklace be settled, now went with the Kratzerei go again! The cat tolerates the collar (but he is otherwise a brave - was a severely traumatized shelter cat 8 years ago), it smells rather pleasant, although initially quite strong, the effect lasts for about 6 weeks. (No problem with the reasonable price) Unfortunately helps the spot of bogacare very little (composed differently), would we prefer, the collar would certainly only with very strong train on (there were most of the other better - but what good is that, if it did not help)! The cat had the way to the collar no single tick - the formally dressed before he has - he runs prefer around in our large grass garden !! A wholly-owned buy recommendation for anyone whose cat mites have problems - and it works very well indeed against ticks, probably against fleas! The collar is black, I mean, the first were green (I may be wrong) and seems to be very well tolerated - including assumes no hair and ignites nothing !!