Both devices are head protection against chocks.
Choice between both types according to the level of noise.
Simple helmet type can be used with ear plugs in situation where exceptional noise protection is needed.
This type with integrated ear noise protection is recommended for situation with permanent noise. This type is mainly used for aircraft operators on ground.
Should also be used by workers on building sites.
Aircraft ground operators can also use the helmet with ear noise protection and integrated ear phones, see Options.
Polyethylene helmet with adjustable head harness.
Conform to EN397