Model 100 Chain-Linked HandcuffsCarbon Treated Steel Slot Lock Double Locking Mechanism Two Keys Included Available in Nickel, Blue, or Melonite Finish The Smith & Wesson's model 100 handcuffs are the carbon nitride finish version of their standard model 100. Formerly called Melonite, the carbon nitride process hardens the carbon steel used to construct these handcuffs and also turns them black. The carbon nitrite process is a case hardening process that leaves a relatively thick,