Product review (1 stars): Eats batteries
I have had this for two weeks and have already had to replace batteries in the outdoor sensor unit.  The batteris were Everready Alkaline, expiration date 2024.  Clearly as other reviewers have stated , this product consumes batteries very quickly.  It's not clear why everyone does not see this problem.  My interior and extertior units are only about 12 feet apart.  At this rate, it will need 52 batteries a year to keep it running.