The cool ring uses PCM material, which freezes naturally at 28 degrees Celsius, eliminating the need for a refrigerator and providing long-lasting coolness. It can be used repeatedly, making it economical and an effective measure against the heat. #✨saki6021's product list✨ ・Please check the actual product photos for the product condition♪ ＊Instant purchase welcome・Midnight silent purchase OK◎ ＊First come, first served for single items ＊Welcome to bulk purchases, please feel free to comment ＊Free shipping! ＊ Shipping is not available on Saturdays, Sundays, and holidays. Shipping will be after Monday. Thank you for your understanding ( ⁎ᵕᴗᵕ⁎ ) ・Please understand that the product is stored at home and will be shipped in simple packaging before purchasing ( ⁎ᵕᴗᵕ⁎ ) Bucci Boo Cool Ring Dog Neck Cooler Heatstroke Prevention Cooling Collar Cool Neck Heatstroke Prevention Button with Luminous Effect Smiling Zoo S 34-66