Flat portion of tool fits under the cylinder head while cupped end fits over the bell in the tube and then compresses the spring allowing for easy access to the spring cap retainer. Designed to remove and install the clip on Harley-Davidson collapsible push rod tubes on Twin Cam and earlier models. No more cut knuckles and scratched engine parts from using a screwdriver between the fins. New improved design with shoulder bolt pivot for smoothness and durability.