Abstract: A size adjuster for helmets for cycling use of the type that can be fixedly connected inside a helmet for cycling use is disclosed. The size adjuster includes an annular structure arranged along the lower periphery of the helmet and is able to be switched between a minimum diameter configuration and a plurality of increased diameter configurations to allow the helmet to be worn by different sized users. The adjuster can include a manual switching device of the configuration of the annular structure and further includes headrest elements for a user connected to the annular structure in a freely orientable manner along at least one axis.

Abstract: Helmet with visor having a shell structure shaped is to at least partly cover the user's head. The visor is hinged to the opposite sides of the shell and mobile with respect to the shell between a raised position and a lowered position where it provides a protective extension of the helmet at the eyes of the user. The visor is manually switchable from the raised and lowered positions by using a magnetic coupling between the visor and the shell which guides and keeps the visor stable in the raised and lowered position and in a plurality of intermediate positions.