Sign up for
Participate with your entry in one of our professional or student awards.Sign up for an award
You are using an outdated browser. Please upgrade your browser to improve your experience.
Sometimes to insert a key into a small keyhole is difficult .This is a keyhole design. Around the keyhole is a concave which can make the whole process of opening the door moving on smoothly .
It is particularly good to the elderly and disabled people.
huizhong zhang xinxin ma xinwei wang yuan kang