The Lockwood Double Cylinder Deadlatch Knob is a powerful deadlock that protects your house and property with the utmost security measures. It is bump and pick resistant with 11 concealed anchorage points to ensure that your property is protected securely at its most vital points, whilst the door frame strengthener provides added security and stability to your door. This deadlock also automatically unlocks the internal knob upon entry, minimising the risk being locked in for added peace of mind. This deadlock also features a hold back function, enabling you to use the door in passage mode when desired. The cut-resistant stainless-steel bolt also increases security at the door, ensuring that the bolt can’t be cut open and broken through. This deadlock also adheres to security and durability requirements of Australian Standard AS4145.2-2008 | SL7D8C6.Adheres to security and durability requirements of Australian Standard AS4145.2-2008 | SL7D8C6|Features a hold back function|Door frame strengthener provides added security and stability|Bump and pick resistant with 11 concealed anchorage points|Cut-resistant stainless-steel bolt