These are Flex-a-lite 24-volt electric fans designed to be used as auxiliary cooling fans, mounted in front of the radiator, to help a belt-driven fan with additional airflow through the radiator at idle or slow vehicle speeds. Some of these come from the factory as pusher fans, while other will need to be converted to a pusher in order to be used as an auxiliary fan. These are not meant to be used as primary cooling fans (mounted behind the radiator) except in special cases.