A mobile locksmiths do a lot more than simply replace lost keys , broken locks or get you back into your home, business or auto. All these could cause the dial to lock one of the numbers in the set and simultaneously unlock the other number completely.
Many times my customers would ask if I could install deadbolts for them while I was at it, and after turning down money a dozen or so times I finally got wise and visited a local locksmith supplier who sold me an install kit and a book of instructions.