One of the formulas that delinquents are using is to break the shield of protection of the lock and then reach the mechanism for opening the lock. There is a large number of doors in the market that have installed this type of shields very cheap of Chinese origin, which offers no guarantee of protection. If one observes it, it looks like a good shield, but in reality, it is useless because the material with which it is made is very weak. These shields are very easy to break with a couple of screwdrivers and a little pressure. After this the criminal only has to get to the cylinder and split it and he already has access to the lock. To be well protected against this, it is very important that the shield be made with hard materials that are impossible to break. There must also be installed an anti-burst cylinder. Naturally, these quality products are much more expensive than those of dubious origin. But what you always have to think about security, is what is the cost so that my family is well protected. A security installation in conditions, costs the same as going to dinner a family night. If we make intelligent calculations we will arrive at the obvious conclusion of what is truly important in our life.