Ubbink's UB19 Mendip vent is a streamlined hooded unit to suit:
Redland, Grovebury
Marley, Mendip
Sandtoft, Double Pantile
The UB19 unit has a free vent area of 22,000mm² and is available in 3 colours.
For the UB19 vent to be converted into a terminal for soil/mechanical ventilation please add the felt sleeve and adaptor 50544180