A replacement cam plug for Honda K-series cylinder heads. The plug closes off the half-moon opening at the end of the camshaft bore, and because it lives in a pressurised oil area it is one of the most common sources of a weeping K-series head. The original item hardens and shrinks with heat cycles, so it is worth replacing any time the valve cover or cam caps come off rather than chasing the leak later. Fitting is straightforward: clean the recess thoroughly, apply a small bead of sealant to the mating faces as the workshop manual specifies, and seat the plug flush before torquing the valve cover down. Suits K-series applications only.