Folder,Trifold,FSTNR,LTR,RD Sold as 10/PK. Heavy-duty tri-fold folders offer a way to compartmentalize your letter-size documents and open to review all three stacks at once. Design features 17 point stock, one 1-1/2" fastener on the side sections and a 2-1/2" prong fastener on center section. Each folder is made using 30 percent post-consumer materials and meets CPG guidelines.