Suburban Furnace Model NT-24S Tune-Up Kit comes in two variations. The first (Kit #1) has a single sense electrode (one wire that goes to the electrode, applicable to S/N above 920500001), the second (Kit #2) has a dual sense electrode (two wires that go to the electrode, applicable to S/N below 920500001). Please verify which kit is applicable to your furnace prior to ordering.
Tune-Up Kit #1 Contents (Links)
Tune-Up Kit #2 Contents (Links):