Or something less expensive: https://www.icydock.com/goods_cat.php?id=146. I have several of these and they've proven more reliable than other four bay devices I've had in the past. I use them as eSATA, but they also have a USB 3.0 port. They either appear as separate drives or you can RAID them, which I've done across two of them for my backup. There's a rebate on them this month, plus other icydock products.
They come with a small plastic holder than fits on the front of the HDD and is screwed on, which allows you to lock the drive into place. They also come with a couple of extra holders as well. That being said, I'm not sure that they're necessary as each drive has a slot to slide into, the holder just makes it easier to slide it in and remove it. You can probably do without it, although I think you'd have to check with icydock to be sure.
Curious - do you have any personal experience with the Mobius Pro 5C? Considering for using with some 2.5" SATA SSDs (non-RAID) and wondering if anyone has read/write speed reports with similar setups.
Took a gamble on the Mobius Pro 5C and it just arrived. Also picked up five Orico 2.5" > 3.5" adapters to use with it. You can slide the SSDs in without needing the screws since the adapters sit with the "floor" in the correct position within the Mobius Pro 5C.
Running with older 2.5" SSDs via USB3 (Inateck KT4004) on MP5,1 gets about 320MB/s write and 340MB/s read direct without RAID involved.
Slightly faster numbers at 340MB/s write and 420MB/s read when connected to a machine with stock/native USB3 controller.
It's an ASMedia controller in case anyone in the future might care/ask.
Might not be a bad solution if you're moving to a new machine and have an MP5,1 filled with SATA SSDs you're looking to repurpose.
I have two Drobo's, a second Gen Drobo 4 bay and the 5D. Speeds on the 5D are plenty fast for my needs, I wouldn't recommend the older second gen 4 bay, it's pretty slow but has proven quite reliable and has been humming along without issue 24/7 since 2011. I've had the 5D running without issue since 2016, also 24/7.
Quick update on the Mobius Pro 5C. Picked up a new MBP16" to replace an aging MBP. Getting 500MB/s+ read and write on these same 2.5" SATA SSD drives via native USB-C 3.1 10Gbps connection when connected to the MBP16" and basically hitting the theoretical advertised maximums for every 2.5" SATA SSD in the enclosure.