www.elitefourum.com/t/plastic-sleeves-for-psa-cases/32011/1
I made a thread asking the same thing about a month ago. I purchased the ones recommended in this thread. I had to wait a week as they were out of stock at the time, but it was worth the wait, they’re awesome!
Edit: It does appear to be superior sleeves that was recommended. So I also recommend them!