A7 2016 is a legacy model to a7 2015 with updated feature . Samsung released its A series for a little premium touch to phones along with A series j series came out before that s3 and s4 and grand etc which all were made of plastic its doesnt feel sort of premium handset although people loved samsung but they were turning towards apple so samsung decided to launch a series with metal in it so all the a serier phones are made of metal unibody so that premuim customer can buy it and its more and far better than plastic