Thank you for your reply and appreciated. In my computer the SSD is M.2  2230 512G SSD, If I am upgrade it can I use M.2 2280 SSD? it is because the M.2 2280 is much longer than M.2  2230.  Thanks again 
Hi, My dell Inspiron 3881 come with 512G SSD and I installed a 1.5Tb 3.5" Hard disk. According to Inspiron 3881 Setup and Specifications it stated M.2 2230 solid-state drive up to 512G and 3.5-inch hard-disk drive up to 2Tb. Does it means I can not upgrade the SSD to higher than 512G and 3.5" hard disk large than 2Tb in the future? In Dell Inspiron 3881 Service manual, page 9 System-board components picture, it shown two hard-drive data cable connector (SATA1) and hard-drive data cable connector (SATA0). Does it means it is ready for a second hard disk to connect? If yes where is the second  hard-drive power cable?.   Thank you for your assistance.  
Dell Insprion 3881 storage