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An HEI's electronic module eliminates the need for breaker points. Triggered by magnetic pulse, it controls dwell time more consistently and improves coil saturation at all engine speeds. Since the module has no moving parts (as noted in this cut-open one), it requires no periodic maintenance, and replacement is only necessary if its internal electronics fail. A daub of heat-sink compound between it and its mounting surface helps dissipate the heat it generates.