I bought this so that TimeMachine on my iMac could back up to it. I just took it out of the box, plugged it in, and it worked. Well, I think TimeMachine popped up a box and I clicked that I wanted to use it. That was it. It's got 3 TB of storage, which is quite a bit. I've had it for a couple of weeks now, it it has gotten 170GB on it. The 3 TB should last a long time. Yes it might have been a bit more pricy than had I gotten a hard drive and an enclosure and a USB cable, reformatted for the Mac, etc. But it just worked. It is USB 3.0, so if you have a new Mac with USB 3 it will go even faster. (My Mac is just USB 2.)
Do not buy this product.It's very slow to open the files.I wasn't ever going to buy another 1.I have about 10 external hard drives and I've never had a problem before.Today I got a message saying it needed to reformat.It did and I lost about 2 TB's of data.I am still highly upset.I took it to a nearby walmart and suggested it be taken off the shelf.I told the walmart employee what had happened.A woman that I wasn't even talking to told me I'd have to take that up with the manufacturer.I didn't buy it from the manufacturer.I purchased it from walmart.From now on,the largest size external hard drive I'll buy is a 1 TB.I got 2 today.I REPEAT.DO NOT BUY THIS PRODUCT!!!!!