512kb or 1Mb Ram expansion for Amiga 1000. Connects to the bus expansion connector.
Below pictures are not the original board:
The pictures of the boards are of 2 different boards (copy of Cardinal Jumbo Ram) produced in the '80s age by a hacker called O.M.A (he produced copies of original products of many devices for Commodore Pet and Amiga 1000, 500, 2000).