Cloth surgical-style mask with nose wire. 
Elastic is adjustable.
Closed (flat) size is approximately 5" wide and 3.5" tall. 
These will provide additional layers but are not medical grade.  I cannot take responsibility if it does not prevent diseases.
For extra protection, you may consider "double masking" or adding a layer should you feel the need.
Please follow the recommendation given by your medical professionals.
Don't forget to cover your nose!