The Morco part is based around the diverter valve section. The diverter valve is a directional water mechanism that only appears in combi boilers. It allows the hot water to be directed to the heating system (radiators, etc.) or to the DHW system (taps, etc.).
"Metalic, circular spindle with a rubber encasement"
Technical specification
TypeDiaphragmManufacturer Model NoMCB2255Brand NameMorco