Pull ring retractable plungers are used in machining applications with limited space as positioners, loading pins, and indexing devices. Easy to grab pull ring allows quick actuation and locks in retracted position. The head of the plunger pin has a rest position where the plunger pin can stay in the retracted position while changing the work piece. To lock, pull the ring back and turn 90°. To release, turn 90° once more and allow pin to engage in perforated holes. Locking patch available upon request.