The Austral Lock Yarra Ridge Sliding Patio Door Deadlock is well-suited to most timber, aluminum and UPVC sliding glass doors, designed to meet both your style and security needs. The deadlock features modern, ergonomic styling and a robust design. It can be locked or unlocked with a key from the outside. Deadlocking is activated by an additional turn of the key from either side. There is also a convenient snib locking function from the inside. (The key overrides the snib). Double cylinder option available. Australian designed and manufactured in Melbourne.