Dear sir, Our company name is kukje safety co.,ltd locating in southkorea who produces gas and dust masks. We would like to test your carbon fifer. Please send to us free sample.Listed below is specification of a.c.f. Activated carbon fiber thin felt Filament diameter ; 6-7 um DHL no. 962880511 Best regards . i . j . yoo-genaral manager Tel ; 88-55-387-2162 Fax ; 88-55-388-2818 Email;yij8809@hanmail.net