From stainless steel rods, bent (4) rods, two for the left side intercyl baffles, two for the right side intercyl baffles. Threaded both ends of each rod, and installed on the bottom of the cylinder baffles. The outboard rods required some customization to make sure they don't contact one of the cylinder oil return lines. Stainless rod against an aluminum oil line sounds like a bad idea for sustained flight.