Class-1, Class-2, etc. refers to the laser safety level in the standard laser safety classification system, with Class-1 being the safest and Class-4 – the most dangerous. Class-1 lasers are typically considered safe in a sense that under normal operating condition they do not emit laser radiation at a level which is harmful to the eye. It is very important to note that all these laser systems have embedded laser sources that are very powerful and can cause significant damage to human eye and skin under direct exposure. Class-1 safety in these systems is achieved through special safety enclosure and safety features that disallow operation of the laser with open door or lid. It is assumed that Class-1 safety will quickly be defeated if the safety features are bypassed.