Insulator for common cheap mini tesla coil (from chinese markets). Adds layer of insulation between outer and inner coil and ensures regular gap → outer coil won't touch inner coil (or come close enough), which could cause the spark to jump in that spot and burn through the coil/wire insulation.
Inner diameter: 22mm
Wall thickness: 1mm
(There is approx. 1mm gap between this and inner coil. Outer coil is tight around this)
Any non-conductive filament is OK.
The author marked this model as their own original creation.