1. thems is bearings
  2. martin, I can't believe that you too are missing the obvious.
  3. It is not a piston head.
  4. magnets? (they are part of a thingamajig)
  5. The object is not a magnet.
  6. counterweight
    KyleK likes this.
  7. FIFY
  8. 3" in diameter and threaded right handed, so it doesn't roll like a wheel... How much does it weigh?
  9. believe the doohickey for these particular counterweights is a camera mounting rig of some sort.
  10. Indeed. The item is a doohickey counterweight.

    The doohickey in question is a digital camera shoulder stabilizer rig.

    c-weights-1.jpg