Heads are an important component of air compressors, which provide air supply to different parts of the engine where needed Mount Type: Two-Piece - Symmetric Head Outside Diameter (mm): 98.6 Head Outside Diameter (in): 3.88 Head Thickness (mm): 36.6 Head Thickness (in): 1.44 Pilot Outside Diameter (mm): 56.9 Pilot Outside Diameter (in): 2.24 Inside Diameter (mm): 20.2 Inside Diameter (in): 0.80, 0.8 Mount Height (mm): 45.2 Mount Height (in): 1.78 Bonded Sleeve: No