Positive: design, ease of use, clamp "Installation", mp3 capable lautstàrke adjustable (= very loud very loud :))
no slots / wall must not be destroyed ..
negative: doorbell button must not only like a bell once normalent be tapped but hold 0.2 seconds, otherwise the signal does not go through
The sounds are almost all useless / awful ..
Batteries (LR6 x4) are after about 4 months flat in normal use (ie buy aufladbarebatterien! + 2400mAh)
am still very zufriedem with the product.
a third would buy :)