Abstract: A plunger tool for producing a special prophylactic is disclosed. The special features of the plunger tool reside in the special curvatures in its shaped section. The shaped section of the plunger tool exhibits an extreme narrowing, at the deepest point of which there may be at least one annular groove. Unlike prior art transitions, the transition from the large diameter to the reservoir section is not steep and straight but takes the form of an S-shaped curve. An exact contour of the annular grooves on the surface of the plunger tool is essential for their production and can be done only by the use of a precision diamond abrasive point.