Brand new, unused S size x 2 【Semi-permanent, Reusable】 Our cool neck ring uses the latest "PCM material" and freezes when the temperature drops below 28 degrees Celsius. When the temperature exceeds 28 degrees Celsius, it absorbs heat and slowly melts while providing a cooling sensation. Once melted, it can be quickly frozen by placing it in cold water or a refrigerator, making it eco-friendly and semi-permanently usable. 【Cooling and Great for Summer Activities】 It's perfect for a wide range of summer activities such as camping, walking, jogging, mountain climbing, fishing, indoor use, fireworks displays, sports観戦, and the office.