During expansion card development, it’s handy to be able to poke around the card with an oscilloscope or multi-meter probe, but you can’t do that when the card is seated in it’s home position in the rack.

The euro extender card plugs into the backplane slot, and then allows the expansion card to be plugged into the extender thus presenting the expansion card forward of the chassis and giving clear, all round access.

The card is passive and contains no electronics and is wired pin to pin.

Construction details, schematics and plans can be found here.