H1-R Racing 100% Synthetic Ester 2T Engine Oil is the ultimate 2-stroke racing engine oil formulated for all power valve 2-stroke engines. Advanced 100% synthetic ester base oils cling to metal, preventing wear in all 2-stroke applications. Clean burning to prevent carbon build-up in combustion chambers and power valve mechanisms. H1-R keeps engines clean and responsive even under the most severe racing conditions. Not suitable for methanol fuel. Bel-Ray developed the H1R synthetic 2-stroke racing oil for race performance 2-stroke engines with a unique power valve formula.