NTG2.5 (COMMAND) with HDD, SD, Navi etc. what type of HDD?

so, there's 40Gb HDD.

can someone show me a link to photo or datasheet of that internal HDD?
is it something common like SATA or IDE, 2.5 or 3.5, or it's SSD, or it's something unique?

Can it be replaced with another (larger capacity) one?
what format system is there (fatX, ntfs, ext,..)?

Thank you for any information!

and another one important question: is thete any possibility to make it read video from HDD??? not only maps and mp3s..