Forgive the necropost but this product is still available. I'm surprised at the negativity being expressed for this dock. True, it's a niche product (most ICY Dock products are, being mostly aimed at the Enterprise sector) but that doesn't mean it's no good.
I've found it to be extremely useful for me. I image my boot drive periodically but imaging is no good if you don't know if the image can be restored. The only way you can test the restorability of an image is to restore it. However, if you attempt to restore an image to your only working boot drive and the restore fails, you are dead in the water and you will have start over from scratch. Better is to remove the drive you just imaged, replace it with another drive, then try to restore the image to it. If the image fails, you still have the original drive to fall back on.
The test should be repeated every now and then to make sure an update to the OS hasn't messed up the ability of your imaging program to make viable images.
I can swap out boot drives in my laptop in around a minute. But it takes 13-25 minutes to swap out the boot drive in my desktop computer, depending on how shaky my old, arthritic hands are that day, because I have to unplug three display port cables and a power cable from the graphics card and pull the card to get to the boot drive. Then, after swapping drives, reverse the procedure to get to where the image can be tested.
With this dock, after shutting down the computer, I can remove the tray the SSD is installed in (I don't even have to move the computer) and replace it with another tray with another SSD installed in it in a minute or less (you can buy extra trays for this dock; I have three with drives installed I keep in rotation). After creating an image, I shut down the computer, swap trays, then boot the computer into a Ventoy drive with my imaging program in it and restore the image. Easy peasy, slick and sleazy.
My only complaint is the pins of an SSD installed in the tray are exposed to possible damage when stored out of the dock. A simple, protective cap included with the tray would have been a good Idea. I made a storage case for two trays from a small, flat plastic box with a hinged lid I dug up and added some antistatic foam I had on hand i it to cradle two trays.
For me, since I swap my boot drive to test my latest image on the first Saturday of each month, I found this to be well worth the money.