Plastic set of 4:

https://www.amazon.com/Dr-Laura-Berman-Intimate-Basics/dp/B018KUTUA2 this says currently unavailable but this looks like the same thing:

https://www.amazon.com/dp/B074BCFB8J/ref=dp_prsubs_1

Soulsource original site: https://soul-source-sd.myshopify.com/collections/silicone-vaginal-dilators

BUT THEY ARE CHEAPER HERE:

https://www.cmtmedical.com/product/soul-source-vaginal-dilators/