Colors: Spring green, lotus root powder, elegant purple, magenta, bean green, navy green Size: S (recommended for children), M (recommended for adult women/people weighing less than 130 pounds), L (recommended for men and people weighing over 130 pounds) Purpose: heatstroke prevention and cooling Attention: Due to different display and lighting effects, the actual color may differ slightly from the image. 2. Due to manual measurement, please allow for some differences and ensure that you do not mind before placing an order.This neck protector is small, light and easy to carry. It is an ideal companion for families, offices, gyms, outdoor activities and other occasions. Designed according to the neck curve, it is comfortable to wear and keeps cool. TPU fabric, stitched firmly, will not tear or break!. Reusable, the neck cooling collar is made of durable material and can shrink after each use. It can be used multiple times, and if not used, it can be stored at room temperature. No battery required! No charger required! Freezing can be done anywhere below 28 °C(82°F), using any air conditioner!, For example, in car air conditioners, office air conditioners, home air conditioners, freezers, refrigerators, cold rooms, and even cold water, crystals can also be crystallized and reused. This PCM gel freezes faster and lasts longer than water! (Can be stored in the refrigerator or air conditioner for 10 minutes, or choose the storage time according to your needs).