A:AnswerNot certified, nor does it have a warranty, only a 15 day store return policy.
I just posted a review on this phone with all the details. I even called Sony, they stated clearly they do not warranty their refurbished Xperia phones.
A:AnswerIt is most definitely the e5306. I use Cricket (with AT&T towers) and have 4g LTE service everywhere my Alcatel Idol 3 bought from Cricket itself had it.
A:Answer2 Gb RAM (Temporary working Memory) (1 Gb is typical, 2 Gb is exceptional, over 2 Gb is unusual)
16 Gb Internal Storage (Space to store Apps, Music, Videos without using additional microsd card)