<prompt> The diameter of Type C fibers is13-20mm4-13mm3-6mm0.5-2mm  <response>: Unmyelinated fibers carrying pain, itch, temperature, and crude touch sensations 0.5 to 2 micrometers in diameter; they are type C fibers in the generalclassification.Ref: Guyton; 13th edition; Chapter 47 Sensory Receptors, Neuronal Circuits for Processing Information 