These coils were used for measurements and development of JF coils.
 In perfect working condition.
 
Dayton Audio 18 gauge perfect layer wound air core inductors are an excellent choice for high quality crossover construction. Features fully annealed refined copper wire, baked enamel insulator, and perfect layer construction. The thin enameled wire permits the tightest windings to minimize DCR and air core construction to ensure no hysteresis and saturation distortions.
Key Features
Highly refined copper wire
Baked enamel insulator
Perfect layer windings
Air core construction
300 watts RMS power handling
±3% tolerance