The services of a locksmith stretch further than just opening or replacing locks and can take many years to perfect the profession. Many locksmiths attend their customers on site or from a shop premises. Locksmiths will provide services for gaining entry to locked car or house or any other lock, replacing locks when a lock fails or recovering key when a key is lost or extracting snapped or broken keys from existing locks. Many locksmiths will also be specialists in gaining entry to safes and hold extensive knowledge of domestic and commercial security.