Header o-ring replacement * Fits hayward h-series millivolt electronic ed1 style pool heater models h2001, h1501, h2501 * Also fits hayward h-series low nox filter models h150fdn, h150fdp, h200fdn, h200fdp, h250fdn, h250fdp, h300fdn, h300fdp, h350fdn, h350fdp, h400fdn, h400fdp * Weighs 3.6-pound