The spherical headed pin, identified by code K 28009, is a precision-machined component used to connect and articulate the main and auxiliary rocker arms (K 28005 and K 28015) in the ZV40/48 engine. Its spherical head allows for smooth rotational and angular motion, reducing friction and wear in the high-stress environment of the valve gear mechanism. Built for strength and reliability, this pin ensures accurate alignment and stable operation of the valve train system, contributing to the overall efficiency and durability of the engine.