A-Trend Helios 3D Voodoo 2
A lot like this Helios 3D Voodoo 2. Since they technically identical (i.e. 12MB) you can pair them to create a SLI set. SLI stands for Scan Line Interleave and doubles the rendering power as well as increasing the maximum resolution to 1024x768. Back in 1998 a Voodoo2 SLI-set was the fastest graphics setup you could have.
Back then you needed two identical branded cards to run in SLI. If you use the FastVoodoo2 drivers you can run a mismatched setup. You do have to have identical amount of RAM on both cards.