Made of soft fabric with a self-cooling and long-lasting cooling gel.The fabric is safe and skin-friendly, and the gel part is flat and resistant to deformation. Lightweight and non-compressive, with buttons to prevent falling off. Can be used after about 20 minutes in the refrigerator. Achieves rapid cooling without over-irritating the skin.Use for indoor or outdoor activities.These neck coolers can be placed in the freezer over and over again without compromising their cooling effect. Freezing time affects the duration, use a replacement pack to extend the time  They stay dry and drip-free after freezing. Suitable for cooling neck, head, wrists, ankles and other parts.