I bought these from Amazon. It's 25 instead of 50. I don't have spares to share though because I'm using what I have left for coin capsule investigator tokens (BGG thing).
https://www.amazon.com/dp/B01NAC0HVT/ref=cm_sw_r_cp_apa_i_DhKIFbQ727FEK
I bought these. They’re more expense than most other capsules that others suggest but they hold up really well. They fit tight but I glued them closed with plastic glue.
I had bought these previously- https://smile.amazon.com/dp/B01NAC0HVT/ - but after upgrading tokens, bought 25mm AIRTITE from OnFireGuy instead, and the difference in quality is immense. The old ones would fall open all the time and didn't feel as nice in your hands. The OnFireGuy capsules are super tight and smooth edged. I love them! Here is a pic of the difference.