This document specifies requirements for construction, design, performance, marking and user information for earmuffs attached to head protection and/or face protection devices, hereinafter referred to as ‘mounted earmuffs’.In particular, it specifies requirements regarding the sound attenuation of mounted earmuffs, measured in accordance with EN ISO 4869-1:2018.The document does not apply to earmuffs outside the size range of headsizes as defined in this standard.Because one model of earmuffs designed to be attached to head protection and/or face protection devices can be fitted to a number of other models and sizes of the carrier, this part of the standard sets out a series of physical and acoustic requirements for earmuffs when fitted to the specified model(s) or size(s) of head protection and/or face protection device.All requirements apply to earmuffs fitted to one of the specified models or sizes of head protection and/or face protection device (the basic combination). An abbreviated set of requirements applies to the same model of earmuffs when fitted to the other specified models or sizes of head protection and/or face protection device (the supplementary combinations).Ergonomic aspects are addressed by taking into account, within the requirements, the interaction between the user, the device and, where possible, the working environment in which the device is likely to be used (see Annex ZA and EN 458).