Source: https://www.amazon.com/Bayer-Seresto-Collar-weights-Protection/dp/B00B8CG5NK/ref=as_li_ss_tl?&imprToken=pKrjEqwG8is8epTxa2fYoQ&slotNum=0&linkCode=sl1&tag=catover05-20&linkId=d1b650d1d91ae52749106ce5e3946be1