Personal protective equipment falling within the scope of the Directive must comply with the basic health and safety requirements set out in Annex II of the Directive. To facilitate conformity with these requirements, harmonized standards are developed at the European or international level by the European Committee for Standardization (CEN, CENELEC) and the International Organization for Standardization in relation to the design and manufacture of the product. Usage of the harmonized standards is voluntary and provides presumption of conformity. However, manufacturers may choose an alternative method of complying with the requirements of the Directive.