Questions about Icy Box Ib-373u3

You have to put the case on, round light at the top and at the back as on the picture, and remove the cover at the front (the one where there are no cables). Then you hold the outer sheet in your hand, fingers on the sides, and with the other hand you push the central part backwards until it comes out completely.

Hello, Yes, Seagate FireCuda works in the ICY BOX IB-373U3.

I would be surprised if NO power supply was included, because not everyone has 50 power supplies with different voltages at home ;-)

Ca. 1.2m

This enclosure (like most USB 3 devices) is downward compatible with USB 2.0. In addition, the internal electronics of such enclosures ensure that the hard drive responds. So it shouldn't matter whether you use USB 2.0 or USB 3.0 on the host device, i.e. your computer (apart from the speed, of course). Regarding the maximum supported hard drive capacity, the manufacturer (Raidsonic) simply says: "Unlimited", so your 3TB hard drive should not be a problem for this enclosure either. Today's devices usually use a 64-bit LBA. According to the specification, the maximum supported hard disk or memory size is 8ZB (Zettabyte), which corresponds to 7,000,000,000 terrabytes. I think that this will still be sufficient for hard disks that will be developed in the near future ;-)