This vest can be worn on various occasions, from work to sports & leisure. The product works best in environments with low to medium humidity. The strength of the airflow determines the cooling effect. When you wear this vest, you avoid heat stress & stay comfortably cool, which increases your performance level. Features Contains a unique cooling technology Machine washable Antibacterial properties Easy to use & reuse Lightweight, non-toxic & reusable Provides up to 15 °C relief cooling below ambient temperature Up to 8 hours of cooling comfort CE marked Activation Activation is easy. Before the first use, soak the shirt in water for one minute & let it dry completely. Then soak the shirt again in clean water for one minute & gently squeeze out any excess water. Your shirt is now ready for use, & will keep you comfortably cool for several hours. For storage, keep your shirt in the special storage tube. It can be stored damp or hung to dry. The shirt becomes stiff when it is dried completely. Sizing T-shirt size = cooling vest size Just take your T-shirt size as a reference to determine your cooling vest size