PLUNGER Main Advantages: High durability, easy get more than 50.000 injections. Cooling Effect. Plunger arrive parking position with near 50-60ºC. Good relation life-price. Holder in stainless steel is a part of the Rod and therefore not a wear part Body in steel rests against the front face of the holder that absorbs the total injection pressure. Split Ring in steel or high strength Cu-alloy is a wear part, replaced with a special plier. Spring Bush made in Soft Steel for high vacuum.