Herobox expand disk

Can the herobox contain a 2.5 disk or a 3.5 disk?
and can it be a ssd or a hdd?

Any 2.5 sata drive (but probably normal 2.5 hdd will be too fat and you will need a slim 2.5 hdd)

how much gb / tb can it contain?
and which brands?

Commercial says " Expandable 2TB 2.5 Inch HDD,1TB SSD". If you want more details write to service@chuwi.com

thank you for your information