I bought Riddex for a tenant to use for roaches. Not only did it not work, but she got a picture of two roaches sitting on top of the Riddex plug-in. Plus their guarantee is not true. I tried in vain to find a phone number or some way to contact them. I returned the units certified mail, requested the refund they guaranteed, and have proof that they received it back in a timely fashion. To no avail. I then found the corporate address and sent a letter requesting a refund. That did not work either. They refused to respond to ANYTHING, except taking your money. I would be happy to email you the photo. read full review »