It’s more or less like this:

.
I do like the Giro, with the magnetic visor (which can be turned over and held on upside down when not needed).
Is this true? Helmets covers save 4W of energy on the bike but what household item could you power with 4W?
Another glorious UCI feck up - ban taping vents which is cheap and available to anyone - enable manufacturers to come up with more expensive solutions not generally available to all!
Maybe like this all day hydrated

.