Product review (5 stars): Difficult to diagnose bad coils which is why experts recommended buying the set of three
Set of three coils received. Shipped a day after ordering from the parts distributor. For my dryer, a Maytag model LDG710, the wiring harness lead wires were a different color than what was supplied on the new coils. (Included replacement part directions say to match the coil lead to same color as dryer wiring which in my case was not possible). After significant investigation, I learned that the coils are AC and the polarity is a non issue. Only exception is the two stacked coils so if you wire them up and notice you are not getting ignition (i.e gas flow), just reverse the wires on one of the two stacked coils.

BTW Difficult to diagnose bad coils which is why experts recommended to buy the set of three. I replaced one at a time but it was the third coil that was bad in my dryer. After examining the old coils, I noticed that one of them would produce an open circuit AFTER heating up which explains why I always had a flame when starting a cold dryer.

I've had the new coils installed for over a month and dryer is working fine with ignition/flame every time. So glad I could find replacement parts to fix my older Maytag gas dryer. They certainly don't make new appliances as robust as these older machines so I hope to keep it running for years to come.