Nostalgic look cast alloy breather cap cover designed to slip over after market chrome push-in style breather caps, this finned cover matches other fin products in the Aussie speed range. This cover is hand polished to a bright finish. is supplied with chrome push in breather cap base part # AS0035. As this is a cast item there is taper on the internal dimensions. measured in the centre 42mm deep, 37mm outer inside edge. 72mm inner opening diameter.