a great product!  Got the units last year because for the first time ever our kitties(3) got fleas and between the advantage and this product got rid of them.  I ordered refill in case we had a problem again.  We have not had a problem with fleas, however did discover black carpet beetles.  Took a few months to track down what they were.  Put on the units with new refills in and have discovered that they like these units!  they are attracted to light so in they go and out they do not come.  have also caught a spider and ant.  These are great for Fleas and other insects.  HIGHLY RECOMMEND!!!