In critical situations you need undisturbed access to your mission notes super quick. These Vinyl envelopes allow you to keep your SOP's, maps, checklists extremely organized and at the ready. Vinyl envelopes hold 4.25in. x 8in. paper. Compatible with of our Pilots Aircrew Checklist Binder and Detachable Flexi 3-Ring Attachment. The envelopes are Made in USA of a sturdy 8mil gauge vinyl.