Original valve cover for Chinese-built GY6 4-stroke 139QMB/QMA engines. The cover is dispatched without an SLS connection [secondary air system]. This means it can be used as a replacement for defective original items, or to blank-off the SLS. This makes the engine quieter and helps it perform better. When installing, you need only change over the crankcase breather hose [small hose with angled connector]. The valve cover gasket is NOT included. When removing the valve cover, we recommend changing the gasket.