Abstract: This invention is a multistable mechanical switching device. It is a bundle of rods surrounded by elastic, which when manipulated can be made to change from one stable close-packed state to another, causing a sudden rearrangement of the rods within the bundle, and producing a snapping noise or click which can be heard and felt with the fingers, interesting visual effects due to the rearrangement of the rods, and various switching and signaling effects. Possible applications of this invention are electrical switches, electronic logic, locks, medical devices, amusement devices, puzzles, science education, toys, executive pacifiers, hand exercisers, and physics and materials science demonstrations.

Abstract: A tamper evident injection syringe of the disposable type is described having a container for storage of the material to be injected, means for expelling the material, an interference collar at one end of the container and a flange attached to the expelling means that is close fitting to the internal wall of the container and having a dimension greater than the interference collar such that the flange cannot pass through the interference means thereby preventing removal of the expelling means and the contents of the syringe. In addition a needle nub is described that permits connection of a needle or catheter and the connection of a tamper evident sealing cap that is easily removable yet when removed cannot be replaced without the removal being evident.