The device has a plastic cover (506) with a ring for surrounding a closure (501) and a neck in assembled configuration, and an operating unit mounted on the ring. The operating unit has tabs (506C) for transmitting thrust force (F'2), parallel to a central axis of the ring, between a key (505) and the cover or between a plate and the operating unit. The tabs are deformed between a configuration, where the length of the tabs parallel to the axis presents a value, and another configuration, where the length presents another value less than the former value. An independent claim is also included for a method for closing a set of recipients.
