Field Backpack (OP)Field Backpack Field backpack features a range of custom pockets for all your teenage engineering devices and more of your everyday tools. Constructed from heavy duty nylon 66 fabric with zip opening that runs all the way down to the base for easy access. Also includes field keychain carabiner and field sit pad. Removable and alterable bottom straps lets you attach anything needed for the journey. fabric is tear and abrasion resistant, nylon 66.