two stage ejector zz169 material:skd11 +skd61 feature 1.design of interlocking mechanism. safe and reliable. 2.the ejector bolt is processed with special technics, easy to process and itallation . 3.some important parts are made of skd61, with higher wear resistance and longer service life. 4.request precision itallation (only 1 set for 1 mold) , make sure the stroke is exactly applicable, or else the product would be easy to damage. 5.4 sizes are available for 4 different loading weights.