WHY CHOOSE INSTA SPEED COOLER? - MADE IN KOREA, SPEEDGOWN’S PATENTED DESIGN WITH SAFE AND NON-REACTIVE REFRIGERANT INSIDE. WHAT IS PCM? - THROUGH PHASE TRANSITION, SOLID TO LIQUID TO SOLID, YOUR INSTA SPEED COOLER ABSORBS A LARGE AMOUNT OF HEAT WHILE KEEPING YOUR BODY COOL AND COMFORTABLE. PCM INSIDE INSTA SPEED COOLER RELEASES ITS STORED HEAT WHEN PUT BACK INTO COOL REFRIGERATOR OR EVEN COLD WATER.