Yes, you locked!

red dot: best of the best
red dot award: design concept 2008

design:
Owen Myunggeun Song	Park Seonkeun
Cho Wonjoo	Woo Byungmin

Yes, You Locked! is a confirmation key that indicates whether a door is locked or unlocked.
 

“Did I lock the door?” Many have had the frustrating experience of locking the door but then forgetting whether they have locked it, despite having just left their homes. This uncertainty invariably prompts them to return and check. The design of the key Yes, You Locked! was inspired by this situation. The user need not worry about forgetting anymore, as this key communicates whether the door is already locked or not. There is a special indicator in the centre of the key that shows if the door is locked. As the key turns in the keyhole, the indicator will revolve and display the “locked” or “unlocked” code. This key is not only beneficial for those with amnesia; it also helps to save time.