Yes... it is... a Hard disk... Actually an IBM 350 disk storage unit, the first hard disk, released in 1966. The disk is the cylinder inside and all the rest is the ton of components required to make it work.
This amazing device stored about 5 millions of 7 bits words (6 bits + one parity bit) so around 4.4 megabytes. Data transfer rate was a blazing 8,800 characters per second.
The 350's cabinet was 60 inches (152 cm) long, 68 inches (172 cm) high and 29 inches (74 cm) deep so it could go through any standard doorway.
(Thanks to Wikipedia for some technical details.)