Nowadays, the hottest tech field is VR, mainly including VR headsets. One type is that mobile phones are put into headsets, with phones to display images and perform operations, which is inexpensive. As for the other type, users have to buy a mainframe, with headsets showing images and mainframe to perform operations. These VR headsets have sound effects but are pricey.
If you just start to experience VR, Google Cardboard is quite suitable, which is good only as a VR product.