Bus powered. Be warned though, since the drive is large, you may need two usb ports to get enough power to the drive.
The usb lead that comes with the caddy has two usb plugs on the end, one is data/power (as usual) and the other is just power.
It should look like the lead above.
Try it with one plug first and see if it works, if not you have to plug the other one in. This is the case with all bus powered drives, USB just can't supply enough juice for some things...
If I got these would the HDD be bus powered, or would I need a power brick?
Bus powered. Be warned though, since the drive is large, you may need two usb ports to get enough power to the drive.
The usb lead that comes with the caddy has two usb plugs on the end, one is data/power (as usual) and the other is just power.

It should look like the lead above.
Try it with one plug first and see if it works, if not you have to plug the other one in. This is the case with all bus powered drives, USB just can't supply enough juice for some things...