Correct answer upstairs

Customized phones, communications companies customize them from manufacturers just like mobile phones

O2 is not a mobile phone brand but a European one Telecom operators and communication industry giants The three main mobile phone operators in the UK - Orange, Vodafone and O2

O2 is a British mobile operator. O2 was separated from BT, the UK's largest telecommunications company, in 2001 and is the sixth largest telecommunications company in Europe. It is located in Slough, England