This part of ISO16365 establishes a system of designation for thermoplastic polyurethane elastomers, which is based on ISO1043 (all parts) and ISO11469. The designation system may be used as the basis for specifications. The designation system is applicable to all thermoplastic polyurethane elastomers. It applies to materials ready for normal use in the form of powder, granules or pellets, unmodified or modified by colourants, fillers or other additives, etc. The types of thermoplastic polyurethane are differentiated from each other by a classification system based on appropriate levels of the designatory properties: hardness; tensile modulus of elasticity (optional); and on information about the alternating hard and soft segments in the main chain, the intended application and/or method of processing, important properties, additives, colour, fillers, and reinforcing materials. It is not intended to imply that materials having the same designation give necessarily the same performance. This part of ISO16365 does not provide engineering data, performance data, or data on processing conditions which may be required to specify a material for a particular application and/or method of processing. If such additional properties are required, it is intended that they be determined in accordance with the test methods specified in ISO16365-2, if suitable. In order to specify a thermoplastic elastomer for a particular application or reproducible processing, additional requirements are intented to be given in data block 5 (see 3.1 and 3.6).