1、Part Number: The chainsaw ignition coil replacing OE number is 503901401, 503620203, 506027207, 544018401 for reference to assist you find exactly what you need. 2、Replacement for Husqvarna: Replacement for Husqvarna 51, 51 EPA, 55, 55 EPA, 55 EU1, 55 Rancher EPA, 61, 254, 257, 261 EPA, 262, 268, 272 XP Chainsaw, 240R, 245R, 245RX, 250R, 250RX String Trimmer, etc. 3、Replacement for Jonsered: Replacement for Jonsered 2054, 2054EPA, 2055, 2095, GR41, GR41 EPA, GR50, GR50 EPA, RS44, RS44 EPA Chainsaw Models to more accurately meet your demands. 4、High Combustion Efficiency: The heavy duty chainsaw ignition coil can effectively improve combustion efficiency and strengthen electrical performance, providing better using experience. 5、Excellent Performance: The premium quality chainsaw ignition coil can provide a higher intensity spark with faster recovery and response, bring you more convenience.