Allstar ALL96480 Black Plastic Engine Connecting Rod Guide Tool for 3/8" or 7/16" Rod Bolt Engine connecting rod guide tool fits 3/8 inch or 7/16 inch rod bolts and is made from quality black plastic Simply slip the tool over the rod bolts to ease piston installation and eliminate rod bolts from hitting the crank A must for any engine builders' toolbox Sold each Backed by a 90-day limited factory warranty