Is an insert needed with the copper infused mask?

No, one side of the mask is a soft knitted fabric layer woven with threads infused with 17% copper.
We currently manufacture 2 copper face masks. You do not need a insert for these masks.
Copper Infused Organic Cotton Barrier Face Mask
Children’s Copper Infused Organic Cotton Barrier Face Mask
Check out this blog post on Why you want a face mask with copper in it?

See our Organic Cotton Face Masks
See our Copper Infused Face Masks
See our Organic Cotton & Silk Face Masks
See our Kids Face Masks