From Tru-Ball:

The World's Smallest Dual Caliper!
The "copper" head, trigger and jaws are made of STAINLESS STEEL using state of the art MIM Technology (Metal Injection Molding). MIM allows shapes that are impossible for CNC machines while providing virtually the same strength as stock material. Don't be fooled with weak powdered metal substitutes!

Features Include:

• * Easy-To-Adjust Web Strap Connection
  * Tuck the head in your sleeve while climbing into your treestand
  * Hardened STAINLESS STEEL Jaws and Trigger
  * Knurled Trigger Grips Your Finger For A Precise Shot
  * Ceramic Coating On Stainless Steel Body Is As Hard As Cutting Tools And Takes Years Of Abuse
  * Rotate The Head 360 Degrees Or Lock The Head In A Fixed Position
  * Pull Trigger To Open Jaws, Let Up To Close