Fixed mobile phone for the elderly (Little Chalfont HP6)

This phone requires a 2G only sim (voda, o2 or EE) it then operates like a fixed phone but without a phone line.
We used it when my mother could no longer get to her phone and then in the care home (where if they could supply a line it was very expensive). It should work on battery or mains power but I don't know if the battery would still last long. Its much cheaper to run than a fixed line - doesn't require connection to a fixed line and there is less spam on the mobile networks.
NB the 2G networks will continue to operate for the next three years at least.

Please say why you want it.
Mike