I have been using this Samsung Galaxy J1( 4g) mobile since one month .It has 8 gb internal memory.The 8 gb of internal memory was used up by more than half out of with pre-installed apps that cannot be removed .So it was not good to use the internal storege even download some apps and some videos.This is 4g mobile .This is Os v 6.0 Android ( marshmallow) verision.It supports expandable memory up to 32 gb.Now these days its not needful.It has 1.3ghz processor and also 1gb ram .Its not comfortable to multitasking.and also when I played games on it gets hangs very much.Rear camera( 5mp) was average.and front camera ( 2mp) was poor quality to takes selfies.It has 4.5 inches screen it was smooth.but desinged not very well.not stylist.Sound clearty was low .So I don’t recommend to buy .