Electromagnetic Induction Heating Coil Heater Hot Coil Copper Coil High Frequency Heating Coil Features The induction coil kit includes seven of the most commonly used prefabricated diameter coils and one free coil, suitable for a wide range of applications. 4 pieces: 1 x 18mm (Internal diameter), 1 x 22mm (Internal diameter), 1 x 28mm (Internal diameter). The length of the free-formed coil is 100cm. Each coil can resist overheating and premature wear, and they are durable enough to be used at least hundreds of times. These induction coils are flexible and can be bent for various purposes, you only need to bend them until they meet your expectations. Our induction coil kits are electroplated to avoid oxidation and ensure contact, thereby providing maximum work efficiency. These coils are insulated to protect you and are coated to prevent wear. If the insulation is damaged, you need to use new coils. Parameter Material: Copper Size: 100cm (free coil) 21x3cm, inner diameter: 1.8cm (Diameter coil) 21x3.5cm, inner diameter: 2.2cm (Diameter coil) 21x4cm, inner diameter: 2.8cm (Diameter coil) Package include 4 x Heating coils