From a project we have ongoing, we have carbon fiber discs to sell.  

These are made from a specialty 8-ply laminate created with a toughened, flame retardant epoxy resin on a standard modulus 3K plain weave carbon fabric. Every other ply is at 60 degrees with a central plane of symmetry. 

The discs have at least a 4.5” (114 mm) diameter usable area and they are .070” (1.80 mm) thick.  

Like other carbon fiber, it is very strong and light.  

Multiple quantities will be discounted.  I have dropped the price to $5 for two of them since I have several more I can sell now.