From the D-Tek site

Compatibility:

The D-TEK FuZion™ GFX 2 comes with all the necessary mounting hardware for the following Video Cards.

ATI:

ATI Radeon® 2900XT -via the 4 mounting holes through the video card using small bracket set.
ATI Radeon® X1000 series -via the 4 mounting holes though the video card.

Nvidia:

Nvidia® 8000 Series -via the 4 mounting holes through the video card and included 8800 mounting and backing plates.
Nvidia® 6800 / 7800 / 7900 series -via the 4 mounting holes through the video card.



D-TEK guarantees compatibility only with video cards following the ATI and Nvidia® reference designs using 4-hole mounting.