Plastic black or grey quality knobs with different diameters. Nut lock.
Specifications:

1. colour: black
2. Ø: 45mm
3. 45mm: 60
   1. A: 6mm
   2. B: 45mm
   3. C: 22mm
   4. D: 24mm
   5. E: 5mm
   6. F: 11mm
   7. H: 23mm