Wichers makes a good point. Copper plugs are tested true for $1.50ea. I do like not having to find a plug with the proper orientated ground strap away from the piston. Replace and go. Im up to 20 purchased sparkplugs now. But I dont think this type of plug would be best suited for a n/a engine were (1) one electric arc is just fine (2) how can you read the plug after a run? When the engine is running a fine line towards failure, youll want to be able to read the plugs. So, the $1.50 copper makes sence n/a.
IMO These plugs are perfect forced induction were multiple arc are needed to reduce chances of blow out.
The company does carry regular style plugs also.