The cover is affixed to the base such that {HEAD ~ the fold} between each flap portion and {TAIL ~ the cover} is arched upwardly away from the base to create a downward biasing force on each flap portion 
between
The cover is affixed to the base such that { HEAD ~ the fold } between each flap portion and { TAIL ~ the cover } is arched upwardly away from the base to create a downward biasing force on each flap portion
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH