Dongya Padlock (3 keys)
 
1. Against versatile key: The internal construction of the lock has innovated & modified from the usual ball to the special multiple layers one. So, the versatile key cannot turn on the lock in any way.
2. Against saw: Hardened steel shackle cannot be cut by saw.
3. Avoid to be prized: the device contains very ahrd Arsteel ball to pin the shackle & it is so strong that it cannot be prized by force.
4. Against drill: Hardened lock shaft cover can be against drill.