Inside ---special cooling material ( Gel ingredients - absorbent polyester + water + preservative + glycerine + Paraben) Soft & Remain Cooling 

 Outside, more durable & lasting( Avoid sharp object )--- Fabric - polyester

  100% Waterproof! 
Naturally cooled , no need to freeze or chill
Not cool enough ? soak in the ice water --- will make you freeze!
Dogs with claws Scrape durable also not easy damage!