Qorpak Fiberboard Specimen Mailer and Clear Glass Boston Round Bottle with Black Phenolic Pulp/Vinyl Lined Cap. Kraft specimen mailers have durable metal ringed bottoms and tops and are furnished with metal screw caps. Meets government regulations for mailing liquids. Primary container and closures included as noted. It is the buyer's responsibility to choose the appropriate container, closure and lining system for the contained substance. 20-400 bottle neck finish.