I purchased a flea collar for my dog and my cat" dual action flea & tick collar II. The pets have been wearing the collars for 4 weeks. These collars DO NOT WORK. My poor pets are still being terrorised by fleas. The collars smell wonderful but DO NOT WORK. I'm on a fixed income and feel the $10 I spent on the collars, which was all I could afford, was completely wasted. I'll have to wait till next month to buy Advantix. Meanwhile I must watch my pets suffer. I'll never buy sargents products again.