Is this some sort of Mac Plus accelerator?

[omgmonsters]

I jumped on this on eBay, thinking it was a Brainstorm Mac Plus accelerator. However, I realize it doesn't have a processor on it.

Anyone have any ideas on what this might be?

 

[Trash80toHP_Mini]

Looks like two of a three card set to me. ROM upgrade and ROM for the Accelerator with cutout for the Killy Klip interfaced accelerator card and a RAM expansion module for the Accelerator. Two layers of a three layer cake?