Closer LookThe Duplus DUP-35 we received has brushed aluminum finish, and will fit nicely in any case with similar color pattern.
The offers a knob and 3 LEDs which show you what setting you have chosen, Drive A, Drive B or Drive A+B.

The backside reveals a blue PCB with input 4-pin power connector and the two outputs for the HDDs;

The included power cables are sufficiently long to be used in mid-tower cases, in a large tower case where the external 3.5” bay is at the top, the cables will be too short, so placement inside the case has to be physically close to the HDDs you will hook up.
InstallationAfter finding a spare 3.5” external bay, you slide in the device, find a spare 4-pin connector from the PSU and plug it in. Then you hook up the two hard drives with the provided power cables are you are good to go.
The three different settings of the knob are clearly explained in the following photo, courtesy of Mitron:

You can only select another mode when you power off the system, this to prevent data loss/corruption.
The use of this device is limited to a target audience looking to have a multi-user, multi-boot, multi-OS system, without use of a software boot manager. While you do loose potential storage space by having one disk powered off while the other is running; you do keep things nicely separated.
The Mitron Duplus DUP-35 works as intended so no qualms there. We only encountered small annoyance when installing the device, if you have a case which uses drive-rail system, you’ll have to improvise to make it fit, in the photo below we added a small metal bar to allow installation with drive-rails.

The only other issue is for convenience sake, as you can see in the photo above there isn’t much room to maneuver and reach the 4-pin power plug, if Mitron could include a 4-pin power cable it will make hooking things up easier for sure.
Conclusive ThoughtsThe Duplus DUP-35 is not a unique product in the market, we have seen disk selectors like this one before, Mitron’s product is compact and easy to use and does so as expected. They include the necessary power cables for PATA/SATA drives and a very complete manual in case you’re inexperienced, and opening your PC case for the first time.
We did not receive pricing info yet; but don’t expect this device to be very expensive.
-- update:
Available for $23 at SideWinderComputers
We like to thank Dennis Lee from
Mitron for allowing us to test their latest product.