VEVOR Induction Heater Coil Kit Induction Coils 8PCS For Removing Rusty BoltsProduct Features 8 PCs Coil Kit This induction coil kit includes seven most commonly used preformed diameter coils and one free coil to remove rusty bolts and fits a wide range of applications. 8 pieces: 2 x 4 5"(20 mm), 2 x 1 1 5" (30 mm), 2 x 1 3 5" (40 mm), 1 x 2" (50 mm). Free forming coil measures 31 1 2" (800 mm). Long Lifespan Each coil can resist overheating and premature wear. They are all durable enough to be used at least several hundred