For Replacement Visors And Care Products, See http://wiki.vorhalle.de:80/index.php?title=Benutzer:GracePeeler152.
Most manufacturers recommend replacing a motorcycle helmet every five to seven years even without a crash, since the internal materials that absorb impact degrade slowly with heat, sweat and UV exposure. The shell can look fine while the protective layer underneath has already lost some of its effectiveness.
Certification is not a formality. It is the baseline that separates a genuine protective helmet from something that only looks the part. Any helmet worth wearing on the road should carry a current, verifiable certification.
Once the shell is formed and cured, it moves through finishing: sanding, painting or leather trimming, and fitting the internal padding and retention system. Every stage is checked before the next begins, since a fault caught early is far cheaper to fix than one found at the end.
None of this needs to be bought at once. Building a complete kit over time, prioritising the areas most exposed in a typical fall, is a realistic way to get there.
For replacement visors and care products, see http://wiki.vorhalle.de:80/index.php?title=Benutzer:GracePeeler152.
Visors are a wear item, not a lifetime part of the helmet, and most riders find a spare on hand is worth having, especially before a long trip.