3.5" Enclosure for two 2.5" drives

I am wondering whether there is such a thingy: An enclosure the size and connectors of 3.5" HDD, with internal connectors for two 2.5" drives. I suppose it must have some kind of on-board RAID controller (0, 1 or JBOD).

Asus have something similar in their VivoPC VM42/VM62 models, but I can't find anything standalone (and Asus do not sell this separately).
 
All of these are just mounting brackets (no electronics inside) to mount 2.5 drive(s) into 3.5" space. What I am looking for is a box with controller where there is single (3.5") SATA connector on the outside, going **somehomw** into two (2.5") SATA connectors inside.

There are plenty of similar boxes where 4 or 6 3.5" drives go into 2 5.25" bays.
 
You might want to take a look at this ebay page and see if any of those devices meet your needs...
http://www.ebay.com/itm/like/291613580598?ul_noapp=true&chn=ps&lpid=82

We've worked with the Rosewill RX-C202 model shown a while back - purchased from Newegg but no longer available. I believe it may have been discontinued by Rosewill. Note this device is designed for installation in a 3 1/2" external drive bay so I don't know if that's what you're looking for since the data & power connectors (one set for each drive) are, of course, at the rear of this mobile rack.
 
@Corroded: The idea was to upgrade a SFF computer with fixed HDD bay. No cables, no connectors - just a bay where 3.5" HDD slides in and locks into place.

@ArtProg - this is still just a piece of metal/plastic, with a backplane designd for two separate SATA connections.

It seems I am looking for an unicorn...