Small component with great effect. The valve stem seal influences for example the oil consumption. Hard "stems" let oil run down the valve, which is then burned. Whenever work is carried out on the dismantled cylinder head, it is recommended to replace the valve stem seals as a precautionary measure anyway.
The gaskets for the intake and exhaust valve are identical in some cars like Yamaha YZF-R / MT / WR 125 or Hond CB 500 R. However, we recommend to adjust the dimensions of the stem seals before ordering.