Abstract: A single-use syringe having a barrel and a plunger is provided. The plunger at least one vane, and the vane is provided with serrations or ratchet teeth. The serrations each have a vertical rear wall and a sloped top edge. A barbed clip is provided that fits on the serrated vane. The barbs on the clip engage the inner wall of the barrel. When the plunger is initially withdrawn, the barbs of the clip engage the inner wall of the barrel and the clip remains in position with respect to the barrel. Because the tops of the serrations are sloped, the ridged/serrated vane of the plunger passes easily under the clip. When the plunger is re-inserted into the barrel, the clip engages one of the vertical rear walls of the serrations and moves along with the plunger deeper into the barrel. If one attempts to re-retract the plunger, the distal wall of the plunger strikes the clip, and the clip is immobilized because the barbs engage the inner wall of the barrel.

Abstract: A single-use syringe having a barrel and a plunger is provided. The plunger at least one vane, and the vane is provided with serrations or ratchet teeth. The serrations each have a vertical rear wall and a sloped top edge. A barbed clip is provided that fits on the serrated vane. The barbs on the clip engage the inner wall of the barrel.

Abstract: A safety seat belt buckle that restricts and limits accidental and intentional buckle release by children. The seat belt buckle has two interdependent release actuators that must be simultaneously depressed to release the seat belt buckle.