We are mow have developed one new style mechanical code lock called ZM mechanical code door lock, it is very new and convenient, the main advantages can be listed as follows: 1,no need battery and key. 2,can locked by itself when close the door. 3,only spend you several Seconds to change the code without remove the lock. 4, weather proof and  shake proof. 5,security. We think it may inspire you, please take your time to visit our updated website for further info. Should you have any question, please contact me freely.