ETook 655 - Key Chain Lock 1100mm x 9mm - Swiss Anti-Drill Piece Lock Cylinder - Level Rating 6

The lock cylinder uses advanced Switzerland with an anti-drilling piece, onlytechnology0.3-0.6mm thickness, and a snaked shape which can effectively prevent technical stealing.
  The lock body comprises 9mm square special hardened steel with heat treatment. lts strong and high toughness well prevents from being sheared, thumped, sawed, and drilled. The diameter and length are both able to be customized.