The UNION Hercules 1K57 padlock, has a vertical sliding shackle which comes through the staple hole making direct attack impossible. Insurance Graded CEN6 and accredited Sold Secure Gold, this lock is ideal fo use in commercial or high security applications. Supplied with 3 keys AVA Available with AVA 10 discKey retention when the padlock is unlockedHardened steel unsprung shackleSuitable for use with UNION 7B018 padbar Anti DrillAnti SawForce ResistantAnti PickTorque ResistantCorrosion Resistant Specification:Shackle type - ConcealedShackle diameter - 16mmShackle clearance - N/ALocking mechanism - Key