External wall ventilation cover grill with gravity flaps  and spigot 
Gravity grille for ventilation, Suitable for external or internal mounting. 4" Spigot Comes with all fixings

Ventilation grilles are used to terminate ventilation ducts. The grilles in the Exclusive series come without a flange (except for the round connections) and feature a modern design. The grilles in the TN series are fitted with a louvre to permit air flow in one direction only.