I can use the one of the USB HUB which the AC adapter does not use. I think that it is worth more than the price. The useless point is screws. When I saw the screw, I understood that this was a bad guy, but with my hand ones I jumped out of the handset holder and hit the handset, so I used to use it without it. As a result, the head of the screw was threaded. It is useless to open a prepared hole. Both of the threads were torn. Be sure to cut at another 2 mm, so it can not be pulled out, it jumps out and it does not have any good things. In addition to that, the driver's hurt is bad and you lick immediately, but it is trivial compared to being screwed.
The corrupt handset on the second floor got broken, and genuine products purchased inexpensive this product as an alternative as it gets over 10,000 yen. Using the output of the current interphone (contact a), connected to the input of the push button of the calling timer set, it worked exactly. The chime side is both adapter and battery, it is possible to carry around, and it became very convenient becoming to understand visitors even in the garden. You can use it alone as it is.