What is this?
A proprietary-RAID enclosure for mixed size disks.
Why did I buy it?
I only recently purchased a used Drobo (Gen 2) and soon after using it I realized that it wasn't fast enough for my needs. Drobo makes a full line of products with various speeds and connection types. After checking out what made the most sense on their drive calculator I decided on the 5D, which works with Thunderbolt 1 & 2.
This hard drive enclosure holds up to five hard drives of any size and combines all of them into one large disk while also providing redundancy. One drive can die and no data will be lost, I will only have to replace that bad drive. And in the future when I need a bigger hard drive, all I need to do is swap out the smallest hard disk for a bigger one and the Drobo will increase the storage space. It's just short of magic.
And to really protect my files, I then backup the contents of the Drobo to Backblaze, an online backup service for only $5/month.
This is how I make sure that all my memories don't disappear in the night.