Resuable insulating sheath for windows

A new reusable insulating sheath selectively positionable over a window opening, said sheath comprising:

• a flexible, transparent sheet of plastic;
• a base member attachable to a perimeter of said window opening, said base member having an upstanding wall portion with at least one downwardly extending base tooth protecting from said upstanding wall portion;
• a locking insert having a rear surface with at least one downwardly extending insert tooth projecting from said rear surface, wherein said at least one downwardly extending base tooth comprises a plurality of downwardly extending base teeth and said at least one downwardly extending insert tooth comprises a plurality of downwardly extending insert teeth;
• and
• coupling means for releasably coupling said locking insert to said base member, whereby a portion of said sheet may be captured between said base member and said locking insert to retain said sheet over said window opening;
• wherein said coupling means comprises an axially aligned slot integrally formed within said base member, said slot having first and second opposed sides with first locking grooves formed in said first side of said slot and second locking grooves formed in said second side of slot;
• and a leg portion integrally connected to said locking insert, said leg portion having axially aligned first and second notches on respectively opposed first and second external surfaces of said leg portion, wherein said first and second notches of said locking insert may be engaged to respective said first and second locking grooves formed in said base member.