Replacement Wheels For Knee-board Hi, Does Anyone Know Where I Can Find Replacement Color Wheels For Fiber-optic Christmas Trees?

Hi, Does anyone know where I can find replacement color wheels for fiber-optic Christmas Trees? - replacement wheels for knee-board

Mine have been caught, fried. The tree is an import, came without a booklet, so I do not use the purchase of spare wheels.
The only one I have is made of plastic (Mylar or Lexan?) And measures 6 1 / 4 "and has the habit to determine many colors.
Any help would be very grateful, believe me!
Cheers,
Fred