A container comprises a cover member and a receptacle member axially displaceable therewithin for selective axial arresting therewith. A polygonal locking neck of the cover member telescopingly receives a polygonal portion of the receptacle member. A circumcircle of the polygonal portion is smaller than an inscribed circle of the polygonal locking neck. The polygonal portion of the receptacle member can be reciprocated about a longitudinal axis between a locked position at which an arresting member is engaged with locking teeth of the receptacle member, and an unlocked position at which the at least one arresting member is disengaged from the locking teeth of the receptacle member. Twisting of the cover member and the receptacle member at opposite senses results in disengaging the locking teeth of the receptacle member from the at least one arresting member of the cover member, into the unlocked position.