Overhead Concealed Trickle Vent Cover - Company Name -

window slot vent   Dan window slot vent

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

Order Casement Window - Trickle Window Slot Vent Set Inside & Out - 400mm - 3180mm²EA Filter Products · Window Material Aluminium; Composite; PVCu; Timber · Vent Type Glazed-in; Slot · Vent Material Metal; Plastic · Fit Flush; Surface Mounted

what is a progressive slot Stocking part F compliant window trickle vents from brands like Glazpart, Greenwood & RW Simon Free next day delivery available Login for discounted trade Internal 4000 compact Link Trickle Vent suitable for PVCu casement windows EQA: 4000mm2 EQ with 13mm rout