The SkyMaxx Roof Vent 400 by 400 Roof Thickness 23-60mm Without LED from Maxxair is suitable for new and replacement installs for 400mm x 400mm apertures.The Skymaxx Roof Vent supports both forced and non-forced ventilation, using clever interchangeable panels that easily switch it between vented and non-vented modes.Features:Manual lift with 3 open positionsPleated screen and blind provides option of full sun, full shade or partial shade/sunSkymaxx lx fits 400 x 400mm roof openingNon-forced ventilationFor 23mm to 60mm roof thickness, no cutting or adapters requiredCe and r43 approval. RoHS compliant