Made for use with 85.5 x 54 mm blank PVC cards. I used the ones in the link below: 

https://www.amazon.com/dp/B0B8CQ5LJW?ref=ppx_yo2ov_dt_b_product_details&th=1

Print flat, some minor supports may be necessary depending on your printer setup, but I wouldn't recommend them. 

I will be uploading separate piece files in a bit.