I bought this "cat special" doorbell saying "even a gadget that will more or less work to finish in a closet," and not at all, this stuff works great! Done lift at three in the morning to see if the clerk wants to finally go, I simply placed the sensor in my veranda (attached with double-sided) there or my cat stands when he wants to return to a dirty beast only has to show up and hop, a charming music (I chose the Pink Panther) tells me I have to get up post-haste to open it ... What progress do you say? And long before I got up five or six times while now, once and this is the right! ! ! Conclusion: the whole family is happy, including the misfortune to cat ... So long life to the inventor of "the bell for cats!"