"The GT-AIR II is the perfect companion for motorcycle trips, long rides and sporty riding sessions. The J-CRUISE II is an excellent partner for motorcycle and scooter rides and for urban mobility. The performance of your helmet can be further enhanced by adapting the interior to your head shape. The different center pad sizes can be used to replace the original part or to customize the helmet to your morphology. The padding of a certain helmet model is interchangeable within its size assignment, for example ""S5"", ""S9"" or ""S13"". ""S5"" corresponds to a thinner padding and ""S13"" to a thicker padding, the thickness being expressed in millimeters. The original part size is indicated on the back of the pad. A well-fitting but comfortable helmet will provide you with pleasure, comfort and safety in all riding situations. The GT-AIR II / J-CRUISE 2 center pad ensures a stable helmet fit and its three-dimensional ribbed structure allows for optimal ventilation and thus effective moisture management. If your helmet's interior padding is worn out after a few years of use and many kilometers, or if it can no longer be cleaned, a replacement will renew the helmet's internal lining and provide a fresh and healthy interior. Compatible with GT-AIR II and J-CRUISE II models. Attached by snap fasteners and a fastening bar. Installation instructions and cleaning tips are available from the GT-AIR II and J-CRUISE II manual."