Fitment：For Stihl MS194 MS194T MS194TC MS 194 194T 194TC Replace 1137 400 1310 / 1137 1309 【Advantage】: The advantages of ignition coils trimmer are less leakage, less energy loss and small volume.Solid material provides corrosion resistance, longer service life, high toughness, and fracture resistance. 【Working】: Ignition coil module magneto stores and releases energy repeatedly at different frequencies according to different engine speed.Ignition coils string trimmer converts the low voltage into thousands of volts for high-voltage spark plug ignition. 【Usage】:Ignition coils replacement directly replace the old or damaged, it is very suitable for repair and replacement. 【Function】: Ignition coils can turn low voltage into high voltage.Perfectly match the flywheel work and emit strong sparks.High performance engine generator lawn mower motor ignition coils provides a higher intensity spark with faster recovery and response.It can improve combustion efficiency and strengthen electrical performance.