WOW! What a wonderful boon to human kind. I was getting 3-5 telemarketing calls per day, many of them robocalls. In the 2 weeks since I installed the Cell Phone Jammer, I've had to block a grand total of only 13 calls - less than one per day. The 5000 blocked numbers it has built in clearly do most of the trick. When a telemarketer does get past that list, it's a very simple matter to hit the red button and kill the call - permanently. Not near the red button and using a cordless phone? Just hit and the call is immediately and permanently blocked. Get calls at the crack of dawn? Block a given number once and it will never awaken you again.