Replacement batteries are quite expensive if you have to replace multiples at the same time, but if your house alarm is off when you are in during the day, these little gadgets are brilliant at providing peace of mind. Loud siren when on that setting, audible all over the house and even in the garden. I keep the 'pulse' setting on my front porch door during the day as so few delivery drivers bother to knock, post covid, just leaving parcels visible in the porch, and it alerts me to the fact there has been a delivery. With the self adhesive pads they are quick and easy to fit wherever you need them. For battery replacement the 'unit' slides out of the housing and slides back in simply with no fuss.

Vienen muy bien envueltos, funcionan a la perfección, tiene 2 reguladores, uno de intensidad del sonido y otro para elegir el tipo de sonido (alarma, aviso o apagado).Viene con cinta de doble cara para pegarlo. En marco de ventana o puerta blanco, se disimula bastante bien y no queda feo ni destaca.

Bonjour , ces petites alarmes s'appliquent trè facilement . le son ( règlable ) est très strident , Je recommande et remercie amazon et ce vendeur.

Work well fitted three within 10 minutes only gripe is the chime is not a Ding Dong but more like a cat getting his throat cut

These are very good,was worried that the heat would bring them off but no still there.