Material: Aluminum(minor parts made by non-aluminum)3 different sized rods: 2.0mm， 2.5mm， 3.0mmBlue=2.0mm， Red=2.5mm， Purple=3.0mmWith this little tool you can build perfect coils every single time with just a twist of your wristPackage: 3PCS * Coil Jigs (Blue，Red，Purple)