Superloud landline phone, and box to connect it to cell phone

This may be of interest to some people here:

It can go really loud, and then even louder with Audio Assist™ buttons (on base phone and cordless). It also has equalizer switches to enhance bass or treble in case that makes sound clearer.

You don’t even need a landline to use it, with this box that converts a cell phone to an RJ11 jack:

I bought the phone for my 100 YO mother who could use hearing aids but doesn’t have them (we’re working on that). She has landline service, but I bought Cell2jack so I could set up the phone at home where I don’t have a landline.