Originally designed for securing commercial shutters and grilles, the 170 series is becoming increasing popular for a wider range of applications where a higher level of security is required. Hardened Steel - Extra protection against hacksaw and cropping attacks. Solid brass body - Added resistance to corrosion 5 pin cylinder with anti-pick mushroom pins - Extra protection against picking. Paracentric keyway - Extra protection against manipulation. 2 keys are supplied with each lock.