A great unit even if it is 10 year old tech, only £20ish on eBay. However it comes with international settings as default. International dial tones and lack of disconnect supervision could result in a difficult and expensive situation for users.
I’ve applied the following settings for UK use. There are many more settings which could be changed – I’ve just not had the need to use the features needing these tones yet.
Outside Dial Tone
Full details are in the manual, here