File folder with fasteners
Smead End Tab File Folder With Fastener, Position 1, Manila, Letter Size, 11 pt, Straight Cut Tab, Reinforced Tab
http://www.filingsupplies.com/Smead-End-Tab-File-Folder-With-Fasteners-p/34110.htm
Oblique folders
Oblique provides organization systems for libraries, corporations, healthcare, education, government, corrections, printers etc..
http://www.filingsupplies.com/Oblique-Filing-System-Oblique-Folders-s/707.htm