Supplier Code: 213603
Filofax Pocket Refill - PVC Card Holder
These card holders are sturdy and good quality. They have four pockets, two on each side. The cards poke out a bit from the top holder.
It would be beneficial if the website description stated that each holds 4 credit cards, not 2 as implied by the photo.
I have more than a dozen of these for different planners that I use for wallets from time to time. Because the cards slide in lengthwise the card holder sits flat in your planner adding precious little bulk.