With DDR4 SO-DIMM RAM, you can replace or expand the RAM of your laptop or NAS. With more RAM. demanding programs work faster on your laptop. That's useful if you edit videos or stream movies on your NAS and 8GB RAM is too slow. SO-DIMM RAM only fits in laptops and NAS. Make sure to choose the speed that's compatible with your motherboard. You can find this in the Task Manager or the manual. DDR4 SO-DIMM RAM only works with laptops and NAS with a DDR4 motherboard.