Sega Saturn combined DRAM and buffer cartridge V1.0C

Found this cartridge incidentally included in a Saturn auction. It was from an ex-development studio but I'm not entirely sure it's purpose; no cables or documents included. It's possible it's a component of a cartdev setup but the cartdev cartridges appear to have a slightly different layout in other auction images I've seen.

Anybody have one of these and know it's purpose?

[GALLERY=media, 2578]Sega Saturn combined DRAM and buffer cartridge V1.0C front by Shane Battye posted Mar 10, 2018 at 10:59 PM[/GALLERY]

[GALLERY=media, 2579]Sega Saturn combined DRAM and buffer cartridge V1.0C rear by Shane Battye posted Mar 10, 2018 at 10:59 PM[/GALLERY]​

 

This development cartridge is for use with the CartDev development system.
Given that the CartDev system occupies the Saturn cartridge slot, this variant of the cartridge has slots for DRAM that can simulate the memory included with RAM expansion cartridges, so that games designed to support the extra RAM could be developed.
The alternative is to connect a RAM expansion cartridge to the pass-through slot at the top of the development cartridge.