THIS SHOULD WORK ON ANY QA50 I THINK THESE ARE ALL OEM HONDA, THEY ARE OUT OF THE ORIGINAL PACKAGING THEY MEASURE TOP TO BOTTOM 48.31 MM OUTSIDE FACE OF VALVE 16.03 MM AND STEM IS 5.46 MM AND THEY ARE MAGNETIC FROM TOP TO ABOUT 1/2 WAY DOWN THE STEM, THEN NOT AT ALL (THIS SOUND RIGHT TO ME) 209G