Hi, Can you advise of the recommended period for replacement of climbing helmets. I note that they conform to EN 397. Do they as per construction hard hats require to be marked with the date of manufacture and the recommended replacement period (3 years)? Are they manufactured in the same manner as a safety helment and as such degrade over time with UV exposures hence the need for replacement etc. What is the recommended replacement period for one of your climbing helmets? Many thanks Dawn