Question about Neonate Bc-5800d

We have been using this phone for about 16 months and have never had any problems with the range - neither in the 3-storey house from the very top to the very bottom, nor on holiday on the terrace 30 m away through several walls.
It is also a top device in other respects - small, reliable, low radiation (no continuous transmission). We would buy it again immediately.

We can easily do this around three massive corners of a house, 100m as the crow flies. We can't use it in an underground car park, nor can we use it in windows with aluminium vapour. Otherwise very reliable and robust: in the last 4 years it has already landed twice in the toilet and been run over by a car. Still runs.