a locking enclosure consisting of first and second members joined at one end by a living hinge and having , respectively , a flexible receptacle with an open recess and a foot portion configured to flex the receptacle as it enters the recess to lock the enclosure in a closed position , where damage to the living hinge and inadvertent opening of the enclosure are resisted by a pair of strips that project up from one end of the recess and down toward the recess bottom from the other end of the recess to engage corresponding slots in the foot .