It takes some strength and several screwdrivers to access the HDD inside the plastic case. The case is secured by clips; you can only open it with a lot of force and you will probably damage the plastic. However, the silicone sleeve will cover any signs of damage, but it might void the warranty.
Inside, you can find the formerly mentioned Toshiba MQ01ABF050 2.5-inch hard drive with a height of just 7 mm. The connection to the PC is established via VLI VL711S-T4 USB 3 SATA Bridge.