The overall cell is 100mm x 15mm x 70mm. The inside of the cell is 90mm x 5mm x 60mm. A standard credit card sized gift card fits well.
This model is designed for the gift card to be horizontal compared to the original's vertical orientation. This allows the cell bars to be shorter. The cell bars on this are also a little thicker so they won't get as wobbly during the print.
In the top of the cell there is a slot to allow for pausing the print to insert the card. If you use the 3MF in Bambu Studio it has a Pause placed before the layer that completely covers the slot. Just drop the card in and hit resume.