This is a hard to find Sonnet Cresendo G3 Nubus upgrade card that installs in the PDS slot of the PowerMac 6100/7100/8100 series models. This is the 233MHz/512K version that will run between 220Mhz - 233MHz depending on the bus speed of the Nubus PowerMac it is installed in. The last picture shows the results after the card was installed in a PowerMac 8100/100AV. Will include a 3.5" floppy disk the the Sonnet System Extension needed to enable the card as well as the Metronome application to measure CPU clock speed. Check on everymac.com for full specs on this card.