The Avideo 24 - A4000 is really a card for adapting the original Avideo 24 for use in an A4000. As the original Avideo connects directly to the motherboard of the A3000 (possibly the A2000 also), it cannot be connected directly to the A4000 motherboard so instead it is attached to the Avideo 24 - A4000 motherboard which plugs into both a Zorro slot, and the video slot. It is unknown whether this card is Zorro II or Zorro III.
Thanks to Gavin Fance