My 1TB external drive followed me around the house AND the office, ALWAYS connected to my laptop by a 12" cable. To be blunt, I HATED that drive! Moving around with my laptop meant moving around with my wired drive. I had to be soooo careful not to drop the drive (or the laptop) and not to disconnect either or both ends of that cable, always fearful that a disconnected cable might render that drive useless, corrupted, or broken.
When I first heard about the Western Digital external 4TB "My Passport Wireless Pro", I could barely believe that such a thing existed. Nonetheless, I rushed over to the Bsst Buy store near me (Glendale, AZ 85308) to grab one. Although I was too late to find it on the shelf, I decided to buy one while I was still in the store.
About a week later my new WIRELESS WD 4TB drive was in my hands. This device is about the same shape and size as a portable external Blu-Ray drive - but it's a bit heavier than any such blu-ray drive. The only cable that is needed comes with the drive. It can be used to charge up the drive's power cell OR it can be used to make a wired connection to any USB port on any other device. BUT said cable IS NOT REQUIRED to make the connection to my laptop so that it can be used as a high capacity backup drive.
If I'm in the kitchen, using my laptop, the "My Passport Wireless Pro" can sit on my nightstand, plugged into the wall outlet to ensure an uninterrupted supply of AC power. And, all the while, the drive is backing up my laptop without any disconnections of any kind! This is a huge improvement in the quality of my life..
The drive ALSO has a port that will accept the memory card you use in your camera(s). And, you can easily save a copy of the document or spreadsheet that you are working on or finished. This, too is huge!
In the interest of full disclosure, please note that I'm using this device with the Time Machine app on my MacBook Pro. And my wife is backing up her Windows laptop to her "My Passport Wireless Pro" drive.
My 4-star rating would have been a 5-star rating 1. IF the device had been in stock when I bought it, and 2. IF it had been easier to get the device configured properly and set up more quickly. But, don't let my criticism put you off. Just know that IF there is a little black tag with white line drawings attached to the included cable (it seems to indicate that one should first set up the drive by connecting the drive to your laptop (or tower) with the included cable, and not by using any wi-fi connection, be sure that the "My Passport....." device is set-up right the first time. I did something wrong and then I had to restore the drive to it's original factory settings and then start all over again. (The online support pages show you how to do the resetting, if necessary).
All-in-all this drive is the best WIRELESS way I've found to backup my daily use of our MacBook, without spending megabucks for an Apple "Time Capsule".