Aussiespeed cast alloy breather cap cover designed to slip over after market chrome push in style breather caps, this ultra large finned cover matches other raked fin products in the Aussiespeed range. The cover is a hand polished bright aluminum 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.