J7 Prime , J7 2016 , On 8 and On 7.
They all are similar / same ( 5.5 inch , Octa Core , Min 2 GB / 16 GB Combo , 13 mega pixel camera ) , but Samsung made sure that there are differences by altering certain components on each devices. Had Samsung made one device with best components from each of the above, it would have been a perfect mid ranger which can be sold in $ 250 - $ 300 range.
Sigh, when will they learn that one good device is better than a couple of average ones.