aluminum red 28mm motorcycle exhaust muffler for crf50 xr50 klx ssr thumpstar lifan 50cc 70cc 90cc 110cc 125cc chinese pit trail dirt bike hiaors aluminum red 28mm exhaust muffler for crf50 xr50 klx ssr thumpstar lifan 50cc 70 90cc 110cc 125cc chinese pit trail dirt bike motorcycle