Frame markings are typically made up of two ratings, one of which is the Style and Protection Rating. This particular range includes safety glasses with frames that have been rated with a 9, which means that they are Resistant to Penetration of Hot Solids, making them suitable for a range of applications that involve dealing with hot debris and flying particles. If you have any questions or need a product recommendation, do not hesitate to contact our customer support team on 020 7501 0594 or via our Contact Us page.