I would normally stock the US made ones from MicroPlastics, Inc. But now that MicroPlastics, Inc was bought out by Essentra, I have had problems restocking plastics. Essentra was taking an extremely long time to incorporate the MicroPlastics product line into their own and I'm not sure they have finished yet.
Still have a few sizes, though:
https://www.greatplainselectronics.com/products.asp?cat=134