... , FDA, ISO13485...PVC Slippers help stimulate blood circulation can relax and gently massage. Certification MSDS, CE, SGS, FDA, ISO13485PVC SlippersFunction1. ... use, soak it into hot water approx. 80-90 degree Celsius for around 3 minutes; for cold use, please place it in ... the freezer for half and hour before usin pvc cold and hot pack, reusable ...