Window-integrated Trickle Vent - No Slot Milling

Yale SlotVent Trickle Vents with Noise Reduction 252mm , 386mm or 467mm Night Slot Ventilation Facility UPVC & Timber Windows · Width:

vents will perform and provide optimum airflow to your home This plastic slot ventilator fits over a 16mm slot in a window and provides an Equivalent Area

window slot vent Premium Trickle Slot Vent for uPVC, Aluminium & Wooden Window - 300mm

slotค่ายใหญ่ It's a trickle vent If you leave it open, it allows a bit of ventilation even when the main window is closed