Each European Directive specifies which conformity assessment procedures can be followed for the specific product. According to the product and the level of risk, the conformity assessment procedures may anticipate a declaration by the manufacturer that the product satisfies the essential requirements, or the involvement of an independent organization, called a Notified Body. In the first case the manufacturer can affix the CE conformity marking on the product and draft by himself the EU Declaration of Conformity. In the second case he can do it only after the authorization and the written affirmation of the Notified Body that the basic requirements are satisfied.