Vent has knurled collar that swivels 60 degrees to direct air flow and volume. Manufactured from 2024-T351 aluminum and anodized in black or grey. 4 mounting holes 7/8″ diameter spaced 2-3/8″ apart with a mounting plate thickness of 0.71″. Total diameter of vent is 2-3/4″. Made in the USA Can be attached with 2″ airduct flange ADF-2 (not included with vent).