This is a guidance system used to protect the ejector pin and holes from premature wear. It is comprised of a special bushing that aligns the two-ejector plates together and a leader pin that in mounted in the bottom clamp plate and into the support plate. The design of how this leader pin is mounted can be made very simple so the mold maker or the molder can disassemble the mold easily and put it back together without being a Houdini. By guiding the ejector plate it prevents uneven pressure and cocking of the plate, which ends up galling all the ejector pins. Many mold makers have this feature as an option on their quotation .In m experience it is well worth the money in a high production molds.