This induction coil kit includes most commonly used preformed diameter coils and free coil to remove rusty bolts;Available For removing rusted bolts and nuts.These coils are insulated for your protection and also outer coating can resist abrasion.If the insulating layer is damaged, a new coil needs to be used.Each coil can resist overheating and premature wear,they are all durable enough to be used at least several hundred times.These Induction Heater Coils are all flexible and can be bent for various purposes,you just need to bend them till they meet your expectations.7 pieces: 2 x 4/5 INCH (20 mm), 2 x 1/5 inch (30 mm), 2 x 3/5 inch (40 mm), 1 x 2 inch (50 mm).Material: Coppercolour: As shownPackage Contents:1 set x induction heater coil kit(7PCS)Only the above package content, other products are not included.Note:Light reflection and different displays may cause the color of the item in the picture a little different from the real thing.The measurement allowed error is +/- 1-3cm.